Questions & Answers
ICSE - Grade - 9
Subject: Physics
Chapter - 02 - Motion in One Dimension
Types of Questions
MCQ
- Which of the following is a scalar quantity?
a) Velocity
b) Displacement
c) Distance
d) Acceleration
Answer: c) Distance - A body is said to be at rest if it:
a) Changes direction
b) Changes its position
c) Does not change its position
d) Moves in a straight line
Answer: c) Does not change its position - Displacement is a:
a) Scalar quantity
b) Vector quantity
c) Constant quantity
d) Zero quantity
Answer: b) Vector quantity - The SI unit of speed is:
a) m
b) km/h
c) m/s
d) cm/s
Answer: c) m/s - The speed of a body at a particular instant is called:
a) Average speed
b) Uniform speed
c) Instantaneous speed
d) Variable speed
Answer: c) Instantaneous speed - When a body covers equal distances in equal intervals of time, it is said to have:
a) Variable speed
b) Uniform speed
c) Constant acceleration
d) Retardation
Answer: b) Uniform speed - Which of the following quantities can be negative?
a) Distance
b) Speed
c) Displacement
d) Mass
Answer: c) Displacement - A car moves 40 km north and then 40 km south. Its displacement is:
a) 80 km
b) 0 km
c) 40 km
d) 20 km
Answer: b) 0 km - Acceleration is the rate of change of:
a) Speed
b) Displacement
c) Velocity
d) Time
Answer: c) Velocity - SI unit of acceleration is:
a) m/s
b) m/s²
c) km/h
d) cm/s²
Answer: b) m/s² - A freely falling body experiences:
a) Uniform velocity
b) No acceleration
c) Acceleration due to gravity
d) Decreasing velocity
Answer: c) Acceleration due to gravity - Which of the following is a vector quantity?
a) Distance
b) Speed
c) Energy
d) Velocity
Answer: d) Velocity - The slope of a displacement-time graph gives:
a) Acceleration
b) Distance
c) Speed or velocity
d) Displacement
Answer: c) Speed or velocity - The area under a velocity-time graph gives:
a) Acceleration
b) Displacement
c) Distance
d) Speed
Answer: b) Displacement - In uniform acceleration, velocity changes:
a) Irregularly
b) Remains constant
c) Equally in equal intervals of time
d) Rapidly
Answer: c) Equally in equal intervals of time - If displacement is zero, average velocity is:
a) Maximum
b) Zero
c) Infinite
d) Equal to speed
Answer: b) Zero - A body moving with uniform speed has:
a) Constant velocity
b) Constant acceleration
c) Zero acceleration
d) Variable speed
Answer: c) Zero acceleration - A body is said to be in motion if:
a) It vibrates
b) It changes its mass
c) It changes position with respect to surroundings
d) It rotates
Answer: c) It changes position with respect to surroundings - The motion of a car on a straight road is:
a) Rotational
b) One-dimensional
c) Two-dimensional
d) Random
Answer: b) One-dimensional - The acceleration due to gravity near Earth’s surface is:
a) 10 m/s²
b) 8.9 m/s²
c) 9.8 m/s²
d) 11 m/s²
Answer: c) 9.8 m/s² - A body thrown upward has:
a) Uniform acceleration downward
b) Uniform velocity upward
c) Zero acceleration
d) Increasing speed upward
Answer: a) Uniform acceleration downward - If a car travels 120 km in 2 hours, its average speed is:
a) 40 km/h
b) 50 km/h
c) 60 km/h
d) 70 km/h
Answer: c) 60 km/h - What does a horizontal line on a velocity-time graph represent?
a) Uniform acceleration
b) Stationary body
c) Uniform velocity
d) Variable acceleration
Answer: c) Uniform velocity - The equation v = u + at is valid for:
a) Uniform motion
b) Uniform acceleration
c) Rotational motion
d) Free fall only
Answer: b) Uniform acceleration - The velocity of a body moving in a straight line with uniform acceleration changes:
a) Linearly
b) Suddenly
c) Not at all
d) Randomly
Answer: a) Linearly - A body moving with decreasing velocity is said to be:
a) Accelerating
b) Retarding
c) In equilibrium
d) Static
Answer: b) Retarding - Displacement-time graph of a stationary body is:
a) Curve
b) Inclined straight line
c) Horizontal straight line
d) Vertical line
Answer: c) Horizontal straight line - If initial velocity is zero and acceleration is constant, displacement is proportional to:
a) t
b) t²
c) t³
d) √t
Answer: b) t² - Which of the following graphs represents uniform acceleration?
a) Curved displacement-time graph
b) Horizontal velocity-time graph
c) Straight velocity-time graph
d) Zig-zag velocity-time graph
Answer: c) Straight velocity-time graph - Which formula is used to find displacement when time and acceleration are known?
a) s = ut + ½at²
b) v = u + at
c) v² = u² + 2as
d) s = vt
Answer: a) s = ut + ½at² - What is the unit of displacement?
a) m/s
b) m
c) m/s²
d) kg
Answer: b) m - In one-dimensional motion, the motion is along:
a) Circular path
b) Curved path
c) Straight line
d) Parabola
Answer: c) Straight line - A velocity-time graph with a downward slope shows:
a) Acceleration
b) Retardation
c) Uniform velocity
d) Stationary object
Answer: b) Retardation - Which one of the following quantities is always positive?
a) Displacement
b) Velocity
c) Acceleration
d) Distance
Answer: d) Distance - Which one does not represent a vector quantity?
a) Force
b) Speed
c) Acceleration
d) Displacement
Answer: b) Speed - Which of these equations gives final velocity?
a) v = u + at
b) s = ut + ½at²
c) s = vt
d) s = v² – u²
Answer: a) v = u + at - What remains constant in uniform circular motion?
a) Velocity
b) Speed
c) Displacement
d) Acceleration
Answer: b) Speed - Which instrument measures instantaneous speed?
a) Odometer
b) Speedometer
c) Thermometer
d) Barometer
Answer: b) Speedometer - If a body moves with zero acceleration, its velocity is:
a) Constant
b) Increasing
c) Decreasing
d) Negative
Answer: a) Constant - Acceleration is zero when:
a) Velocity is changing
b) Velocity is uniform
c) Displacement is zero
d) Time is zero
Answer: b) Velocity is uniform - Velocity becomes negative when:
a) Object stops
b) Object reverses direction
c) Object accelerates
d) Time is zero
Answer: b) Object reverses direction - Equation v² = u² + 2as is used to find:
a) Time
b) Final velocity
c) Displacement
d) Acceleration
Answer: b) Final velocity - When a body returns to starting point, its displacement is:
a) Equal to distance
b) Negative
c) Positive
d) Zero
Answer: d) Zero - Which of these is true for uniform motion?
a) Acceleration is non-zero
b) Velocity changes
c) Displacement = speed × time
d) Speed is variable
Answer: c) Displacement = speed × time - A steeper slope in velocity-time graph indicates:
a) Higher displacement
b) Higher speed
c) Higher acceleration
d) Lower acceleration
Answer: c) Higher acceleration - What is the displacement of a body moving in a circle and completing one round?
a) 2πr
b) 0
c) πr
d) r
Answer: b) 0 - The direction of acceleration due to gravity is:
a) Upward
b) Downward
c) Horizontal
d) Variable
Answer: b) Downward - If a velocity-time graph is a curve, the motion has:
a) Uniform acceleration
b) Variable acceleration
c) Zero acceleration
d) Uniform velocity
Answer: b) Variable acceleration - Which of these does not affect acceleration due to gravity?
a) Mass of object
b) Altitude
c) Latitude
d) Depth
Answer: a) Mass of object - What is the acceleration when a car moves with constant velocity?
a) Maximum
b) Zero
c) Increasing
d) Decreasing
Answer: b) Zero
Fill in the Blanks
- A body is said to be in __________ if it changes its position with respect to its surroundings.
Answer: motion - The quantity which has only magnitude and no direction is called a __________ quantity.
Answer: scalar - The shortest distance between initial and final position of a body is known as __________.
Answer: displacement - Displacement is a __________ quantity.
Answer: vector - The actual path length travelled by a body is called __________.
Answer: distance - Distance is a __________ quantity.
Answer: scalar - SI unit of distance and displacement is __________.
Answer: metre - Speed is defined as the rate of change of __________.
Answer: distance - Velocity is defined as the rate of change of __________.
Answer: displacement - SI unit of speed and velocity is __________.
Answer: metre per second - A body covering equal distances in equal intervals of time is said to be moving with __________ speed.
Answer: uniform - A body covering unequal distances in equal intervals of time is said to be moving with __________ speed.
Answer: non-uniform - The speed of a body at any particular instant is called __________ speed.
Answer: instantaneous - Average speed is given by total __________ divided by total time.
Answer: distance - Average velocity is given by total __________ divided by total time.
Answer: displacement - A body at rest has __________ displacement.
Answer: zero - Acceleration is defined as the rate of change of __________.
Answer: velocity - SI unit of acceleration is __________.
Answer: metre per second square - Acceleration due to gravity is denoted by the symbol __________.
Answer: g - The value of acceleration due to gravity near Earth’s surface is approximately __________ m/s².
Answer: 9.8 - A body moving with constant velocity has __________ acceleration.
Answer: zero - A body moving with increasing velocity has __________ acceleration.
Answer: positive - A body moving with decreasing velocity has __________ acceleration.
Answer: negative - A body falling freely under gravity undergoes __________ acceleration.
Answer: uniform - The slope of displacement-time graph gives __________.
Answer: velocity - The area under a velocity-time graph gives __________.
Answer: displacement - The slope of a velocity-time graph gives __________.
Answer: acceleration - A horizontal line on a displacement-time graph represents a body at __________.
Answer: rest - A straight inclined line on displacement-time graph indicates __________ velocity.
Answer: uniform - A curved line on a displacement-time graph indicates __________ velocity.
Answer: variable - A horizontal line on velocity-time graph indicates __________ velocity.
Answer: uniform - A straight line with positive slope on velocity-time graph shows __________ acceleration.
Answer: uniform - A straight line with negative slope on velocity-time graph shows __________.
Answer: uniform retardation - When a body returns to its starting point, its displacement is __________.
Answer: zero - The first equation of motion is __________.
Answer: v = u + at - The second equation of motion is __________.
Answer: s = ut + ½at² - The third equation of motion is __________.
Answer: v² = u² + 2as - In the equation v = u + at, ‘a’ stands for __________.
Answer: acceleration - In the equation s = ut + ½at², ‘s’ stands for __________.
Answer: displacement - In the equation v² = u² + 2as, ‘u’ stands for __________.
Answer: initial velocity - The motion of a body falling freely under gravity is an example of __________ acceleration.
Answer: uniform - Motion in a straight line is also called __________ motion.
Answer: one-dimensional - A car moving at constant speed on a straight road has __________ velocity.
Answer: uniform - Displacement can be __________, negative, or zero.
Answer: positive - Distance is always __________.
Answer: positive - The unit of speed in the CGS system is __________.
Answer: cm/s - If time taken is doubled and distance remains constant, speed will become __________.
Answer: half - The instrument used to measure instantaneous speed in vehicles is __________.
Answer: speedometer - A body thrown upward moves against the acceleration due to __________.
Answer: gravity - When a body moves with changing acceleration, it is said to have __________ acceleration.
Answer: variable
Name the Following
- Name the quantity that has only magnitude and no direction.
Answer: Scalar quantity - Name the quantity that has both magnitude and direction.
Answer: Vector quantity - Name the SI unit of displacement.
Answer: Metre - Name the SI unit of speed.
Answer: Metre per second - Name the SI unit of acceleration.
Answer: Metre per second square - Name the quantity which refers to the actual path length covered.
Answer: Distance - Name the shortest distance between the initial and final positions of a moving body.
Answer: Displacement - Name the physical quantity that is the rate of change of displacement.
Answer: Velocity - Name the physical quantity that is the rate of change of distance.
Answer: Speed - Name the physical quantity that is the rate of change of velocity.
Answer: Acceleration - Name a vector quantity among speed, mass, velocity, and energy.
Answer: Velocity - Name the scalar quantity among displacement, force, acceleration, and distance.
Answer: Distance - Name a type of motion in which a body moves in a straight line.
Answer: One-dimensional motion - Name the instrument used to measure instantaneous speed.
Answer: Speedometer - Name the graph used to study velocity change over time.
Answer: Velocity-time graph - Name the graph used to study position change over time.
Answer: Displacement-time graph - Name the graph whose slope gives velocity.
Answer: Displacement-time graph - Name the graph whose slope gives acceleration.
Answer: Velocity-time graph - Name the graph whose area under the curve gives displacement.
Answer: Velocity-time graph - Name the graph whose horizontal line indicates a body at rest.
Answer: Displacement-time graph - Name the graph whose horizontal line indicates uniform velocity.
Answer: Velocity-time graph - Name the equation of motion that gives velocity after time t.
Answer: v = u + at - Name the equation of motion that gives displacement after time t.
Answer: s = ut + ½at² - Name the equation of motion that gives final velocity in terms of displacement.
Answer: v² = u² + 2as - Name the force responsible for a freely falling body.
Answer: Gravitational force - Name the acceleration experienced by a freely falling body.
Answer: Acceleration due to gravity - Name the symbol used for acceleration due to gravity.
Answer: g - Name the approximate value of acceleration due to gravity on Earth.
Answer: 9.8 m/s² - Name the term for acceleration in the opposite direction of motion.
Answer: Retardation - Name the condition when displacement is zero but distance is not.
Answer: Round trip motion - Name the type of motion when a body moves with constant speed in a straight line.
Answer: Uniform motion - Name the motion where speed changes with time.
Answer: Non-uniform motion - Name the motion in which velocity changes at a constant rate.
Answer: Uniform acceleration - Name the motion of an object thrown vertically upward.
Answer: Motion under gravity - Name the motion of a body falling freely under gravity.
Answer: Free fall - Name a situation where acceleration is zero but velocity is not.
Answer: Uniform velocity motion - Name the quantity calculated by dividing distance by time.
Answer: Speed - Name the quantity calculated by dividing displacement by time.
Answer: Velocity - Name the quantity calculated by dividing change in velocity by time.
Answer: Acceleration - Name the point on a displacement-time graph where the object changes direction.
Answer: Turning point - Name the characteristic of speed that it cannot be __________.
Answer: Negative - Name the quantity that is always greater than or equal to displacement.
Answer: Distance - Name the quantity that can be positive, negative, or zero.
Answer: Displacement - Name the device that measures the total distance travelled by a vehicle.
Answer: Odometer - Name the term for the speed measured at any given instant.
Answer: Instantaneous speed - Name the term for the velocity measured at any given instant.
Answer: Instantaneous velocity - Name the average of all velocities over total time taken.
Answer: Average velocity - Name the average of all speeds over total time taken.
Answer: Average speed - Name the line representing rest in a displacement-time graph.
Answer: Horizontal line - Name the motion in which both speed and direction keep changing.
Answer: Non-uniform velocity motion
Answer in One Word
- What is the SI unit of displacement?
Answer: metre - What is the SI unit of speed?
Answer: metre/second - What is the SI unit of acceleration?
Answer: metre/second² - What is the SI unit of velocity?
Answer: metre/second - What quantity measures how fast something is moving?
Answer: speed - What is the rate of change of displacement called?
Answer: velocity - What is the rate of change of velocity called?
Answer: acceleration - What do you call the motion in a straight line?
Answer: linear - What is the actual path length travelled called?
Answer: distance - What is the shortest distance between two points?
Answer: displacement - What type of quantity is distance?
Answer: scalar - What type of quantity is displacement?
Answer: vector - Which quantity has both magnitude and direction?
Answer: vector - Which quantity has only magnitude?
Answer: scalar - What is the acceleration due to gravity symbol?
Answer: g - What is the approximate value of g near Earth?
Answer: 9.8 - What instrument measures instantaneous speed?
Answer: speedometer - What instrument measures total distance travelled?
Answer: odometer - What kind of motion occurs with equal distance in equal time?
Answer: uniform - What kind of motion occurs with unequal distance in equal time?
Answer: non-uniform - What do you call the speed at any particular instant?
Answer: instantaneous - What do you call the average of total distance over time?
Answer: average - What term is used for motion against gravity?
Answer: upward - What kind of acceleration occurs when velocity decreases?
Answer: retardation - What kind of acceleration occurs when velocity increases?
Answer: acceleration - What kind of line on a displacement-time graph shows rest?
Answer: horizontal - What graph has velocity on y-axis and time on x-axis?
Answer: velocity-time - What graph has displacement on y-axis and time on x-axis?
Answer: displacement-time - What does the area under a velocity-time graph give?
Answer: displacement - What does the slope of a velocity-time graph give?
Answer: acceleration - What does the slope of a displacement-time graph give?
Answer: velocity - Which type of motion has constant velocity?
Answer: uniform - Which type of motion has changing velocity?
Answer: non-uniform - What is another word for negative acceleration?
Answer: retardation - Which equation of motion is v = u + at?
Answer: first - Which equation of motion is s = ut + ½at²?
Answer: second - Which equation of motion is v² = u² + 2as?
Answer: third - What is velocity when displacement is zero?
Answer: zero - What is the direction of gravitational acceleration?
Answer: downward - What do you call acceleration that does not change?
Answer: uniform - What quantity can be positive, negative, or zero?
Answer: displacement - What quantity is always positive?
Answer: distance - What is the time taken for a round trip called?
Answer: total - What is the type of motion of a freely falling object?
Answer: accelerated - What is the motion called when only gravity acts?
Answer: freefall - What kind of graph shows changing acceleration?
Answer: curved - What do you call motion in one straight direction?
Answer: rectilinear - What is the rate of change of speed without direction?
Answer: scalar - What is the initial velocity in a body starting from rest?
Answer: zero - What is the velocity when a body returns to start point?
Answer: zero
ICSE - Grade 9 - Physics
All Chapters
- Chapter 1 Measurement and Experimentation
- Chapter 2 Motion in one dimension
- Chapter 3 Laws of Motion
- Chapter 4 Pressure in fluids and Atmospheric pressure
- Chapter 5 Upthrust in Fluids, Archimedes’ Principle and Floatation
- Chapter 6 Heat and energy
- Chapter 7 Reflection of light
- Chapter 8 Propagation of Sound waves
- Chapter 9 Current Electricity
- Chapter 10 Magnetism
ICSE - Grade 9 - Chemistry
All Chapters
- Chapter 1 The Language of Chemistry
- Chapter 2 Chemical Changes and Reactions
- Chapter 3 Water
- Chapter 4 Atomic Structure and Chemical Bonding
- Chapter 5 The periodic table
- Chapter 6 Study of the first Element Hydrogen
- Chapter 7 Study of Gas laws
- Chapter 8 Atmospheric Pollution
ICSE - Grade 9 - Mathematics
All Chapters
- Chapter 1 Rational and Irrational Numbers
- Chapter 2 Compound Interest [Without Using Formula]
- Chapter 3 Compound Interest [Using Formula]
- Chapter 4 Expansions
- Chapter 5 Factorisation
- Chapter 6 Simultaneous Equations
- Chapter 7 Indices
- Chapter 8 Logarithms
- Chapter 9 Triangles
- Chapter 10 Isosceles Triangles
- Chapter 11 Inequalities
- Chapter 12 Midpoint and Its Converse
- Chapter 13 Pythagoras Theorem
- Chapter 14 Rectilinear Figures
- Chapter 15 Construction of Polygons
- Chapter 16 Area Theorems
- Chapter 17 Circle
- Chapter 18 Statistics
- Chapter 19 Mean and Median
- Chapter 20 Area and Perimeter of Plane Figures
- Chapter 21 Solids
- Chapter 22 Trigonometrical Ratios
- Chapter 23 Trigonometrical Ratios of Standard Angles
- Chapter 24 Solutions of Right Triangles
- Chapter 25 Complementary Angles
- Chapter 26 Coordinate Geometry
- Chapter 27 Graphical Solution
- Chapter 28 Distance Formula
ICSE - Grade 9 - Biology
All Chapters
- Chapter 1 Introducing Biology
- Chapter 2 Cell: The Unit Of Life
- Chapter 3 Tissues: Plant And Animal Tissue
- Chapter 4 The Flower
- Chapter 5 Pollination and Fertilization
- Chapter 6 Seeds: Structure and Germination
- Chapter 7 Respiration in Plants
- Chapter 8 Five Kingdom Classification
- Chapter 9 Economic Importance of Bacteria and Fungi
- Chapter 10 Nutrition
- Chapter 11 Digestive system
- Chapter 12 Skeleton: Movement and Locomotion
- Chapter 13 Skin: The Jack of all trades
- Chapter 14 The Respiratory System
- Chapter 15 Hygiene: [A key to Healthy Life]
- Chapter 16 Diseases: Cause and Control
- Chapter 17 Aids to Health
- Chapter 18 Health Organizations
- Chapter 19 Waste Generation and Management
ICSE - Grade 9 - History
All Chapters
- Chapter 1 – The Harappan Civilisation
- Chapter 2 – The Vedic Period
- Chapter 3 – Jainism and Buddhism
- Chapter 4 – The Mauryan Empire
- History — Chapter 5
The Sangam Age - Chapter 6 – The Age of the Guptas
- Chapter 7 – Medieval India — (A) The Cholas
- Chapter 8 – Medieval India — (B) The Delhi Sultanate
- Chapter 9 – Medieval India — (C) The Mughal Empire
- Chapter 10 – Medieval India — (D) Composite Culture
- Chapter 11 – The Modern Age in Europe — (A) Renaissance
- Chapter 12 – The Modern Age in Europe — (B) Reformation
- Chapter 13 – The Modern Age in Europe — (C) Industrial Revolution
ICSE - Grade 9 - Civics
All Chapters
- Chapter 1: Our Constitution
- Chapter 2: Salient Features of the Constitution — I
- Chapter 3: Salient Features of the
- Constitution — II
- Chapter 4: Elections
- Chapter 5: Local Self-Government — Rural
- Chapter 6: Local Self-Government — Urban
ICSE - Grade 9 - Geography
All Chapters
- Ch 1 – Earth as a Planet
Ch 2 – Geographic Grid: Latitudes and Longitudes
Ch 3 – Rotation and Revolution
Ch 4 – Earth’s Structure
Ch 5 – Landforms of the Earth
Ch 6 – Rocks
Ch 7 – Volcanoes
Ch 8 – Earthquakes
Ch 9 – Weathering
Ch 10 – Denudation
Ch 11 – Hydrosphere
Ch 12 – Composition and Structure of the Atmosphere
Ch 13 – Insolation
Ch 14 – Atmospheric Pressure and Winds
Ch 15 – Humidity
Ch 16 – Pollution
Ch 17 – Sources of Pollution
Ch 18 – Effects of Pollution
Ch 19 – Preventive Measures
Ch 20 – Natural Regions of the World
Find the Odd Man Out
- Distance, Displacement, Velocity, Acceleration
Answer: Distance
Explanation: Distance is a scalar quantity; the others are vector quantities. - Metre, Kilogram, Second, Metre/second²
Answer: Kilogram
Explanation: Kilogram is a unit of mass, others are related to motion. - Speed, Time, Velocity, Acceleration
Answer: Time
Explanation: Time is a fundamental quantity; others are derived from motion. - 9.8 m/s², Velocity, Acceleration, Displacement
Answer: 9.8 m/s²
Explanation: It is a specific value of acceleration due to gravity, others are general quantities. - Uniform speed, Non-uniform speed, Retardation, Uniform velocity
Answer: Retardation
Explanation: Retardation involves decreasing speed; others describe motion types. - Speed, Mass, Distance, Time
Answer: Mass
Explanation: Mass is unrelated to motion in one dimension; others define or affect motion. - m/s, m/s², kg, m
Answer: kg
Explanation: Kilogram measures mass, others are motion-related units. - Displacement, Force, Acceleration, Time
Answer: Time
Explanation: Time is scalar; others are vector quantities. - Velocity, Displacement, Distance, Acceleration
Answer: Distance
Explanation: Distance is scalar; the rest are vectors. - Speedometer, Odometer, Ammeter, Stopwatch
Answer: Ammeter
Explanation: Ammeter measures electric current; others are used in motion measurement. - Velocity-time graph, Displacement-time graph, Bar graph, Acceleration-time graph
Answer: Bar graph
Explanation: Bar graph is not used to represent motion. - m/s, m², m, cm
Answer: m²
Explanation: m² is a unit of area, not used in linear motion. - Displacement, Distance, Area, Velocity
Answer: Area
Explanation: Area is not a quantity involved in one-dimensional motion. - Acceleration, Retardation, Constant speed, Increasing speed
Answer: Constant speed
Explanation: Constant speed means zero acceleration; others involve change in speed. - Free fall, Uniform acceleration, Projectile, Stationary
Answer: Stationary
Explanation: Stationary means no motion; others involve motion. - Speed, Velocity, Direction, Distance
Answer: Direction
Explanation: Direction is not a physical quantity, others are measurable. - Scalar, Vector, Velocity, Force
Answer: Scalar
Explanation: Scalar is a type of quantity, others are vectors. - Uniform velocity, Non-uniform velocity, Instantaneous velocity, Friction
Answer: Friction
Explanation: Friction is a force; others are types of velocity. - Motion, Rest, Acceleration, Velocity
Answer: Rest
Explanation: Rest is the absence of motion; others describe motion. - m/s, cm/s, km/h, m²/s
Answer: m²/s
Explanation: m²/s is not a valid unit of speed or velocity. - g, a, u, d
Answer: d
Explanation: ‘d’ usually denotes distance (scalar), others are motion-related variables. - v = u + at, v² = u² + 2as, s = ut + ½at², P = VI
Answer: P = VI
Explanation: It is a formula from electricity, not motion. - Velocity, Displacement, Acceleration, Area
Answer: Area
Explanation: Area is not a motion-related quantity. - Horizontal line, Sloped line, Curved line, Pie chart
Answer: Pie chart
Explanation: Pie chart is not used to represent motion. - 0, Positive, Negative, Scalar
Answer: Scalar
Explanation: Scalar is a type of quantity, others are values of displacement or velocity. - Mass, Displacement, Velocity, Acceleration
Answer: Mass
Explanation: Mass is not a kinematic quantity. - North, East, Upward, 10 m
Answer: 10 m
Explanation: It is magnitude only; others are directions. - Time, Instantaneous velocity, Average speed, Distance
Answer: Time
Explanation: Time is a base quantity; others are motion descriptors. - Displacement, Force, Acceleration, Weight
Answer: Displacement
Explanation: Displacement is kinematic; others are dynamic quantities. - Retardation, Deceleration, Speed, Negative acceleration
Answer: Speed
Explanation: Speed is scalar; others imply decreasing velocity. - Motion, Direction, Force, Distance
Answer: Force
Explanation: Force is not a kinematic term. - Rest, Zero velocity, Stationary, Accelerating
Answer: Accelerating
Explanation: Accelerating involves motion; others indicate no motion. - m/s, cm/s, kg/s, km/h
Answer: kg/s
Explanation: kg/s is not a unit of speed. - u, v, s, W
Answer: W
Explanation: W stands for work; not used in equations of motion. - Distance, Scalar, Direction, Time
Answer: Direction
Explanation: Direction is not a scalar quantity. - Speed, Acceleration, Friction, Velocity
Answer: Friction
Explanation: Friction is a force, not a kinematic quantity. - Speed, Distance, Time, Energy
Answer: Energy
Explanation: Energy is not directly related to linear motion. - Odometer, Stopwatch, Speedometer, Thermometer
Answer: Thermometer
Explanation: Thermometer measures temperature, not motion. - Vector, Velocity, Mass, Displacement
Answer: Mass
Explanation: Mass is scalar; others are vectors. - 1st Equation, 2nd Equation, 3rd Equation, Newton’s Law
Answer: Newton’s Law
Explanation: It relates force; others are kinematic equations. - Scalar, Magnitude, Vector, Newton
Answer: Newton
Explanation: Newton is a unit; others are quantity types. - Horizontal line (s-t), Increasing slope (s-t), Horizontal line (v-t), Pie chart
Answer: Pie chart
Explanation: Pie chart is not used in motion representation. - Mass, Time, Length, Momentum
Answer: Momentum
Explanation: Others are base quantities; momentum is derived. - Friction, Gravity, Magnetism, Speed
Answer: Speed
Explanation: Speed is not a force. - s = ut + ½at², v² = u² + 2as, v = u + at, F = ma
Answer: F = ma
Explanation: F = ma is Newton’s 2nd law; others are kinematic. - Uniform velocity, Variable velocity, Rest, Work
Answer: Work
Explanation: Work is not a state of motion. - Mass, Volume, Acceleration, Temperature
Answer: Acceleration
Explanation: Acceleration is a derived vector quantity; others are scalar. - Second, Hour, Metre/second, Minute
Answer: Metre/second
Explanation: Others are time units; m/s is speed. - Velocity, Acceleration, Power, Displacement
Answer: Power
Explanation: Power is unrelated to one-dimensional motion. - Graph, Formula, Unit, Generator
Answer: Generator
Explanation: Generator is a device; others are study tools in motion.
Match the Pair
Set 1 – Basic Concepts
Match the following:
1. Distance
2. Displacement
3. Speed
4. Velocity
5. Acceleration
Column B:
a) Vector quantity
b) Rate of change of velocity
c) Scalar quantity (path length)
d) Rate of change of displacement
e) Scalar quantity (no direction)
Correct Answers:
1 – c
2 – a
3 – e
4 – d
5 – b
Set 2 – Units
Match the following:
1. Speed
2. Displacement
3. Acceleration
4. Time
5. Velocity
Column B:
a) Metre
b) Second
c) Metre/second
d) Metre/second²
e) Same as speed but with direction
Correct Answers:
1 – c
2 – a
3 – d
4 – b
5 – e
Set 3 – Graphical Understanding
Match the following:
1. Displacement-time graph
2. Velocity-time graph
3. Slope of displacement-time graph
4. Area under velocity-time graph
5. Slope of velocity-time graph
Column B:
a) Acceleration
b) Indicates velocity
c) Gives displacement
d) Graph with time on x-axis
e) Graph with velocity on y-axis
Correct Answers:
1 – d
2 – e
3 – b
4 – c
5 – a
Set 4 – Equations of Motion
Match the following:
1. First equation
2. Second equation
3. Third equation
4. ‘u’ in equations
5. ‘s’ in equations
Column B:
a) s = ut + ½at²
b) Initial velocity
c) Displacement
d) v = u + at
e) v² = u² + 2as
Correct Answers:
1 – d
2 – a
3 – e
4 – b
5 – c
Set 5 – Motion Types
Match the following:
1. Uniform motion
2. Non-uniform motion
3. Retardation
4. Free fall
5. Zero displacement
Column B:
a) Acceleration in opposite direction
b) Equal distance in equal intervals
c) Body returns to starting point
d) Gravity is the only force
e) Unequal distance in equal intervals
Correct Answers:
1 – b
2 – e
3 – a
4 – d
5 – c
Set 6 – Concept Identification
Match the following:
1. Scalar quantity
2. Vector quantity
3. Speedometer
4. Odometer
5. Velocity
Column B:
a) Vector quantity with direction
b) Instantaneous speed
c) Distance measuring device
d) Distance, speed
e) Displacement, acceleration
Correct Answers:
1 – d
2 – e
3 – b
4 – c
5 – a
Set 7 – Real-Life Examples
Match the following:
1. A car moving in a straight line at constant speed
2. A train slowing down
3. A ball thrown vertically upward
4. A body falling freely
5. A body at rest
Column B:
a) Uniform motion
b) Retardation
c) Constant acceleration due to gravity
d) No change in position
e) Negative acceleration during rise
Correct Answers:
1 – a
2 – b
3 – e
4 – c
5 – d
Set 8 – Characteristics
Match the following:
1. Displacement is zero
2. Speed is constant
3. Acceleration is zero
4. Direction changes
5. Velocity changes
Column B:
a) In non-uniform motion
b) When object returns to origin
c) Uniform motion
d) Curved path motion
e) No change in velocity
Correct Answers:
1 – b
2 – c
3 – e
4 – d
5 – a
Set 9 – Derived Quantities
Match the following:
1. Velocity
2. Acceleration
3. Distance
4. Time
5. Displacement
Column B:
a) Base quantity
b) Vector from initial to final point
c) Vector: displacement/time
d) Scalar: path length
e) Vector: change in velocity/time
Correct Answers:
1 – c
2 – e
3 – d
4 – a
5 – b
Set 10 – Directional Motion
Match the following:
1. Positive velocity
2. Negative velocity
3. Zero velocity
4. Positive acceleration
5. Negative acceleration
Column B:
a) Body moving forward
b) Body slowing down
c) No change in position
d) Body gaining speed
e) Body moving backward
Correct Answers:
1 – a
2 – e
3 – c
4 – d
5 – b
Short Answer Questions
- What is displacement?
Answer: Displacement is the shortest distance between the initial and final positions of a moving body in a specific direction. - What is speed?
Answer: Speed is the rate of change of distance with respect to time. - What is velocity?
Answer: Velocity is the rate of change of displacement with respect to time. - What is acceleration?
Answer: Acceleration is the rate of change of velocity with respect to time. - What is the SI unit of displacement?
Answer: The SI unit of displacement is metre (m). - What is the SI unit of speed?
Answer: The SI unit of speed is metre per second (m/s). - What is the SI unit of velocity?
Answer: The SI unit of velocity is metre per second (m/s). - What is the SI unit of acceleration?
Answer: The SI unit of acceleration is metre per second squared (m/s²). - What is meant by uniform speed?
Answer: A body has uniform speed if it covers equal distances in equal intervals of time. - What is meant by non-uniform speed?
Answer: A body has non-uniform speed if it covers unequal distances in equal intervals of time. - What is uniform acceleration?
Answer: Uniform acceleration means equal change in velocity in equal intervals of time. - What is retardation?
Answer: Retardation is negative acceleration or a decrease in velocity with time. - Define instantaneous speed.
Answer: Instantaneous speed is the speed of a body at a particular instant of time. - Define average speed.
Answer: Average speed is the total distance travelled divided by the total time taken. - Define average velocity.
Answer: Average velocity is the total displacement divided by the total time taken. - Can displacement be negative?
Answer: Yes, displacement can be negative if the final position is in the opposite direction to the initial one. - Can speed be zero?
Answer: No, speed is always a positive quantity or zero when the body is at rest. - What is the acceleration due to gravity near Earth?
Answer: The acceleration due to gravity near Earth is approximately 9.8 m/s². - What does the slope of a displacement-time graph represent?
Answer: The slope of a displacement-time graph represents velocity. - What does the slope of a velocity-time graph represent?
Answer: The slope of a velocity-time graph represents acceleration. - What does the area under a velocity-time graph represent?
Answer: The area under a velocity-time graph represents displacement. - What kind of motion has zero acceleration?
Answer: Uniform motion has zero acceleration. - Can displacement be greater than distance?
Answer: No, displacement is always less than or equal to distance. - What is the nature of the displacement-time graph for uniform motion?
Answer: It is a straight line inclined to the time axis. - What is the nature of the velocity-time graph for a body with uniform acceleration?
Answer: It is a straight line with constant slope. - What is the first equation of motion?
Answer: The first equation of motion is v = u + at. - What is the second equation of motion?
Answer: The second equation of motion is s = ut + ½at². - What is the third equation of motion?
Answer: The third equation of motion is v² = u² + 2as. - What does ‘u’ stand for in equations of motion?
Answer: ‘u’ stands for initial velocity. - What does ‘v’ stand for in equations of motion?
Answer: ‘v’ stands for final velocity. - What does ‘s’ stand for in equations of motion?
Answer: ‘s’ stands for displacement. - What does ‘a’ stand for in equations of motion?
Answer: ‘a’ stands for acceleration. - What does ‘t’ stand for in equations of motion?
Answer: ‘t’ stands for time taken. - What is meant by one-dimensional motion?
Answer: Motion along a straight line is called one-dimensional motion. - What is the velocity of a body at rest?
Answer: The velocity of a body at rest is zero. - What is the displacement when a body returns to its starting point?
Answer: The displacement is zero. - Give one example of one-dimensional motion.
Answer: A car moving on a straight road is an example of one-dimensional motion. - Is velocity a scalar or vector quantity?
Answer: Velocity is a vector quantity. - Is speed a scalar or vector quantity?
Answer: Speed is a scalar quantity. - Can average speed and average velocity be equal?
Answer: Yes, when motion is in a straight line in the same direction. - What is the graph for a stationary object on a displacement-time graph?
Answer: It is a horizontal straight line. - What is the unit of time in the SI system?
Answer: The unit of time in SI system is second (s). - What instrument measures instantaneous speed in vehicles?
Answer: A speedometer measures instantaneous speed. - What instrument measures total distance travelled in vehicles?
Answer: An odometer measures total distance travelled. - What is negative acceleration called?
Answer: Negative acceleration is called retardation. - What is the value of displacement in a round trip?
Answer: The value of displacement in a round trip is zero. - What does a curved displacement-time graph indicate?
Answer: It indicates non-uniform motion. - What does a steeper velocity-time graph slope represent?
Answer: It represents greater acceleration. - When is the average velocity equal to zero?
Answer: When the total displacement is zero. - What is the motion of a body falling freely under gravity called?
Answer: It is called free fall.
Puzzles
- I am always greater than or equal to my twin, but I never know direction. What am I?
Answer: Distance
- I can be positive, negative, or even zero, but I always know the way. What am I?
Answer: Displacement
- I can exist even if you’re standing still for a moment. I’m the whisper of change. What am I?
Answer: Acceleration
- I am zero when your journey begins and often rise with time. You see me on your dashboard. What am I?
Answer: Speed
- My graph is flat when you’re still, steep when you move. I’m drawn with time. Who am I?
Answer: Displacement-time graph
- I change when you change direction. I am not loyal to your path, only your net move. What am I?
Answer: Displacement
- Without direction, I wander cluelessly. With direction, I gain meaning. What concept am I referring to?
Answer: Velocity
- I’m the space covered, not the way you went. I don’t care if you turned or bent. What am I?
Answer: Distance
- If I’m constant, your slope is straight. If I vary, your line curves. What graph am I?
Answer: Displacement-time graph
- My slope is your change in speed. Guess who I am?
Answer: Velocity-time graph
- If you run in a circle and stop at the start, I’m zero. But my twin is not. Who am I?
Answer: Displacement
- I describe how you speed up or slow down. I am the change-maker. What am I?
Answer: Acceleration
- Two bodies start from the same point. One moves east, the other west. Who has greater displacement?
Answer: Both can have equal displacement in opposite directions.
- My unit is m/s². I may scare you in free fall. Who am I?
Answer: Acceleration
- I measure how fast your position changes. Who am I?
Answer: Velocity
- A train moves with constant speed but has changing velocity. How is this possible?
Answer: Because the direction changes (e.g., on a curved track)
- If I return home after a jog, my displacement is?
Answer: Zero
- If you accelerate but your speed doesn’t change, what’s happening?
Answer: You are changing direction (like circular motion)
- My value is never negative and always counts everything, even retracing. Who am I?
Answer: Distance
- I’m read on a speedometer, not on a map. What kind of speed am I?
Answer: Instantaneous speed
- If slope = 0 on a displacement-time graph, the object is?
Answer: At rest
- What changes in negative acceleration?
Answer: Velocity decreases
- I’m acceleration, but my direction is opposite to motion. What special name do I get?
Answer: Retardation
- A bus moves 20 km north and 20 km south. What is the total displacement?
Answer: Zero
- Who am I if I am the ratio of change in position to change in time?
Answer: Velocity
- I grow when you speed up, fall when you brake. But if you turn, I still exist. What am I?
Answer: Acceleration
- You drive for 2 hours at 60 km/h, then 2 hours at 40 km/h. What’s the average speed?
Answer: 50 km/h
- If my direction flips, my sign does too. I’m a quantity with purpose. Who am I?
Answer: Displacement or Velocity
- If your velocity is constant but time increases, what happens to acceleration?
Answer: It remains zero
- You see me in curves, slopes, and lines. I’m the language of motion. What am I?
Answer: Graphs
- A ball rises and falls. Where is its speed zero?
Answer: At the highest point
- If a car moves backward with increasing speed, what is its acceleration?
Answer: Negative
- A line slopes downward in a velocity-time graph. What does this show?
Answer: Retardation
- Two vehicles have same speed but different velocities. Why?
Answer: Because they move in different directions
- A journey begins and ends at the same place. What’s the net displacement?
Answer: Zero
- I help you know how far, not where. I’m blind to direction. Who am I?
Answer: Distance
- You start a race, stop halfway, and come back. Is your distance more than your displacement?
Answer: Yes
- If slope = infinity on a displacement-time graph, what’s happening?
Answer: Sudden, undefined jump in position (theoretical only)
- I’m always changing in a curved velocity-time graph. Who am I?
Answer: Acceleration
- I live in formulas like v² = u² + 2as. I connect three friends: speed, time, and space. What am I?
Answer: Equation of motion
- If your graph area is large, you’ve moved a lot. Who am I?
Answer: Displacement (from velocity-time graph)
- If the time is constant but velocity rises, what increases?
Answer: Acceleration
- A man walks 10 m north, 10 m south. What’s his total distance?
Answer: 20 meters
- Same man, what’s his displacement?
Answer: 0 meters
- You move in a zigzag but end up at the start. Is your speed zero?
Answer: No
- My quantity is fixed unless direction changes. I’m friend to displacement. Who am I?
Answer: Velocity
- The longer the time with same change in velocity, the smaller I get. Who am I?
Answer: Acceleration
- I go up with steep slope in v-t graph. What kind of motion is this?
Answer: Uniform acceleration
- A body at rest has what kind of velocity?
Answer: Zero
- You climb 10 steps up, 10 steps down. What’s your net displacement?
Answer: Zero
Difference Between:
- Difference between Distance and Displacement
- Distance is the total path length covered by a body, irrespective of direction.
- Displacement is the shortest distance between the initial and final position of the body in a specific direction.
- Difference between Speed and Velocity
- Speed is the rate of change of distance with time and is a scalar quantity.
- Velocity is the rate of change of displacement with time and is a vector quantity.
- Difference between Scalar and Vector quantities
- Scalar quantities have only magnitude and no direction (e.g., mass, speed, distance).
- Vector quantities have both magnitude and direction (e.g., displacement, velocity, force).
- Difference between Uniform and Non-uniform Speed
- Uniform speed means equal distances are covered in equal intervals of time.
- Non-uniform speed means unequal distances are covered in equal intervals of time.
- Difference between Uniform and Non-uniform Velocity
- Uniform velocity means equal displacement is covered in equal intervals of time in a fixed direction.
- Non-uniform velocity means displacement or direction or both change with time.
- Difference between Instantaneous Speed and Average Speed
- Instantaneous speed is the speed of a body at a particular moment.
- Average speed is total distance travelled divided by total time taken.
- Difference between Instantaneous Velocity and Average Velocity
- Instantaneous velocity is the velocity of a body at a specific instant.
- Average velocity is total displacement divided by total time taken.
- Difference between Rest and Motion
- A body is said to be at rest if it does not change its position with respect to its surroundings.
- A body is said to be in motion if it changes its position with respect to its surroundings.
- Difference between Acceleration and Retardation
- Acceleration is the rate of increase of velocity with time.
- Retardation is the rate of decrease of velocity with time (also called negative acceleration).
- Difference between Speed and Acceleration
- Speed is the distance travelled per unit time.
- Acceleration is the rate of change of velocity per unit time.
- Difference between Uniform Acceleration and Non-uniform Acceleration
- Uniform acceleration occurs when velocity changes by equal amounts in equal intervals of time.
- Non-uniform acceleration occurs when velocity changes by unequal amounts in equal intervals of time.
- Difference between Motion in One Dimension and Two Dimensions
- One-dimensional motion occurs along a straight line in a single direction.
- Two-dimensional motion occurs in a plane, requiring two coordinates to describe the motion.
- Difference between Positive and Negative Acceleration
- Positive acceleration increases the velocity of a body.
- Negative acceleration (retardation) decreases the velocity of a body.
- Difference between Velocity-Time and Displacement-Time Graph
- Velocity-time graph shows how velocity changes with time and its slope gives acceleration.
- Displacement-time graph shows how displacement changes with time and its slope gives velocity.
- Difference between Uniform Motion and Non-uniform Motion
- In uniform motion, the body covers equal distances in equal intervals of time.
- In non-uniform motion, the body covers unequal distances in equal intervals of time.
- Difference between Free Fall and Vertical Throw Upwards
- Free fall is downward motion under gravity, where velocity increases.
- Vertical throw upwards is motion against gravity, where velocity decreases.
- Difference between Displacement and Distance (Based on Values)
- Displacement can be zero, positive, or negative.
- Distance is always positive or zero, never negative.
- Difference between Path Length and Displacement
- Path length refers to the actual route taken by the body.
- Displacement is the straight-line distance between start and end points.
- Difference between Motion and Change of Position
- Motion is a continuous change in position over time.
- Change of position may occur without continuous movement (e.g., shifting suddenly).
- Difference between Equations of Motion (Graphical vs Algebraic Method)
- Graphical method derives equations using area and slope concepts from graphs.
- Algebraic method derives equations using mathematical manipulation of variables.
Assertion and Reason
Answer Codes:
A. Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
B. Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
C. Assertion is true, but Reason is false.
D. Assertion is false, but Reason is true.
- Assertion: Displacement can be zero even when distance is not zero.
Reason: Displacement is the shortest distance between initial and final positions.
Answer: A - Assertion: A body moving with uniform speed has uniform acceleration.
Reason: Uniform speed means constant velocity.
Answer: C - Assertion: Speed is always positive.
Reason: Speed is a scalar quantity and has no direction.
Answer: A - Assertion: Velocity can be negative.
Reason: Velocity is a vector quantity.
Answer: A - Assertion: Distance is a vector quantity.
Reason: It has both magnitude and direction.
Answer: D - Assertion: Acceleration is the rate of change of velocity.
Reason: Acceleration is a scalar quantity.
Answer: C - Assertion: Average speed is always equal to average velocity.
Reason: Both are ratios of distance or displacement over time.
Answer: C - Assertion: Displacement can never be greater than distance.
Reason: Distance is always equal to or greater than displacement.
Answer: A - Assertion: A body at rest has zero displacement.
Reason: Displacement occurs only when there is change in position.
Answer: A - Assertion: A body moving with constant velocity has zero acceleration.
Reason: Acceleration is change in velocity per unit time.
Answer: A - Assertion: The SI unit of speed is m/s.
Reason: Speed is the rate of change of displacement.
Answer: C - Assertion: A body moving with uniform acceleration covers equal distances in equal intervals of time.
Reason: In uniform acceleration, velocity changes equally in equal intervals.
Answer: C - Assertion: The area under a velocity-time graph gives displacement.
Reason: The slope of a velocity-time graph gives speed.
Answer: B - Assertion: A horizontal line on a displacement-time graph means body is moving.
Reason: Slope of the displacement-time graph represents velocity.
Answer: C - Assertion: Displacement is a vector quantity.
Reason: It is described by magnitude and direction.
Answer: A - Assertion: A freely falling body moves with uniform velocity.
Reason: The acceleration due to gravity is constant.
Answer: C - Assertion: Retardation is also known as negative acceleration.
Reason: It causes the velocity of a body to decrease.
Answer: A - Assertion: Acceleration due to gravity has a constant value near Earth.
Reason: It is approximately 9.8 m/s² and directed downwards.
Answer: A - Assertion: The value of acceleration due to gravity changes with location.
Reason: It depends on mass of the object.
Answer: C - Assertion: A car goes 100 m forward and then 100 m backward; its displacement is 0.
Reason: Displacement considers the net change in position.
Answer: A - Assertion: Speed and velocity both are vectors.
Reason: Vectors have both magnitude and direction.
Answer: D - Assertion: If a body is accelerating, its speed must be increasing.
Reason: Acceleration is the rate of change of velocity.
Answer: C - Assertion: A stationary body has zero velocity.
Reason: Velocity is displacement per unit time.
Answer: A - Assertion: The first equation of motion is v = u + at.
Reason: It is used for uniformly accelerated motion.
Answer: A - Assertion: Distance can be zero even if a body moves.
Reason: Distance is a vector quantity.
Answer: D - Assertion: A velocity-time graph with a straight sloping line indicates uniform acceleration.
Reason: Slope of velocity-time graph gives acceleration.
Answer: A - Assertion: Displacement-time graph for uniform motion is a straight line.
Reason: Uniform motion implies constant velocity.
Answer: A - Assertion: Speed is directionless.
Reason: It is a vector quantity.
Answer: C - Assertion: A body thrown vertically upward has constant acceleration.
Reason: Acceleration due to gravity always acts downward.
Answer: A - Assertion: In free fall, speed of the body increases.
Reason: Gravity pulls the body downward.
Answer: A - Assertion: An object can have acceleration even if its speed is constant.
Reason: Acceleration depends on change in velocity, not just speed.
Answer: A - Assertion: A curved displacement-time graph indicates variable velocity.
Reason: The slope changes continuously in such a graph.
Answer: A - Assertion: In rectilinear motion, displacement and distance are always equal.
Reason: Both measure the length of path travelled.
Answer: C - Assertion: The third equation of motion is v² = u² + 2as.
Reason: It relates velocity and displacement directly.
Answer: A - Assertion: In one-dimensional motion, a body can have negative velocity.
Reason: Direction is taken into account in velocity.
Answer: A - Assertion: Speedometer measures instantaneous speed.
Reason: It shows the average speed over a long distance.
Answer: C - Assertion: Distance covered by a body is always non-negative.
Reason: Distance is a scalar quantity.
Answer: A - Assertion: A body under uniform acceleration moves equal distances in equal times.
Reason: Acceleration is constant in uniform acceleration.
Answer: C - Assertion: Displacement and velocity are always in the same direction.
Reason: Velocity depends on displacement.
Answer: B - Assertion: The velocity of a body at rest is zero.
Reason: There is no change in position.
Answer: A - Assertion: Acceleration due to gravity depends on the mass of the falling object.
Reason: Heavier objects fall faster.
Answer: D - Assertion: Uniform velocity means acceleration is zero.
Reason: Velocity remains constant with time.
Answer: A - Assertion: The direction of velocity is same as that of displacement.
Reason: Velocity is the rate of change of displacement.
Answer: A - Assertion: SI unit of time is minute.
Reason: Time is measured in seconds in SI units.
Answer: D - Assertion: Acceleration can be positive, negative, or zero.
Reason: It depends on whether speed is increasing, decreasing, or constant.
Answer: A - Assertion: All moving objects are accelerating.
Reason: Acceleration is a change in velocity.
Answer: C - Assertion: A car moving in a straight line with increasing speed has acceleration.
Reason: Speed and velocity both are increasing.
Answer: B - Assertion: The area under the acceleration-time graph gives velocity.
Reason: Velocity is obtained by integrating acceleration over time.
Answer: A - Assertion: Displacement-time graph with a zero slope shows constant velocity.
Reason: Zero slope means displacement is changing uniformly.
Answer: C - Assertion: The unit “m/s²” is used for acceleration.
Reason: It expresses change in velocity per unit time.
Answer: A
True or False
- Distance is a scalar quantity.
Answer: True - Displacement can be greater than distance.
Answer: False - Velocity is the rate of change of displacement.
Answer: True - Speed can be negative.
Answer: False - Displacement can be zero even when distance is not zero.
Answer: True - Acceleration is a scalar quantity.
Answer: False - A body moving at constant speed has zero acceleration.
Answer: True - Velocity has both magnitude and direction.
Answer: True - Distance and displacement are always equal.
Answer: False - A straight line displacement-time graph indicates uniform motion.
Answer: True - Area under a velocity-time graph gives acceleration.
Answer: False - Speed is the rate of change of velocity.
Answer: False - Acceleration can be positive or negative.
Answer: True - The SI unit of speed is m/s².
Answer: False - Speedometer measures instantaneous speed.
Answer: True - In uniform motion, acceleration is constant and non-zero.
Answer: False - A horizontal line on a velocity-time graph indicates uniform velocity.
Answer: True - Displacement is always positive.
Answer: False - A body at rest has zero velocity.
Answer: True - Velocity is a scalar quantity.
Answer: False - Uniform acceleration means equal changes in velocity per unit time.
Answer: True - Distance can be zero even if the object has moved.
Answer: False - Odometer measures displacement.
Answer: False - Displacement-time graph of a stationary object is a horizontal line.
Answer: True - The slope of velocity-time graph gives speed.
Answer: False - The unit “cm/s” can be used for speed.
Answer: True - Displacement can be negative.
Answer: True - Velocity is always greater than speed.
Answer: False - v = u + at is valid only for uniform acceleration.
Answer: True - Speed is a vector quantity.
Answer: False - A car moving with decreasing speed is said to be accelerating.
Answer: False - Acceleration is the slope of displacement-time graph.
Answer: False - A car reversing direction may have negative velocity.
Answer: True - If a body returns to its starting point, its displacement is zero.
Answer: True - A zero slope on displacement-time graph means object is at rest.
Answer: True - Velocity-time graph with upward slope shows decreasing velocity.
Answer: False - Retardation is also called negative acceleration.
Answer: True - Displacement depends only on initial and final positions.
Answer: True - The direction of acceleration due to gravity is upward.
Answer: False - The formula v² = u² + 2as can be used to calculate displacement.
Answer: True - If a moving object covers equal distances in equal time intervals, it has uniform speed.
Answer: True - A velocity-time graph with a curved line shows variable acceleration.
Answer: True - Displacement and distance are the same in circular motion.
Answer: False - The value of acceleration due to gravity is the same on all planets.
Answer: False - Instantaneous velocity is the same as average velocity.
Answer: False - A freely falling body accelerates due to gravity.
Answer: True - An object can be moving and still have zero acceleration.
Answer: True - Displacement can be more than distance in any motion.
Answer: False - Scalar quantities have both magnitude and direction.
Answer: False - A falling object increases speed at a constant rate near Earth’s surface.
Answer: True
Long Answer Questions
- Define distance and displacement. Mention any two differences.
Answer:
Distance is the actual path length covered by a body during motion. It is a scalar quantity and always positive.
Displacement is the shortest distance between the initial and final positions of a body, with direction. It is a vector quantity.
Differences:
- Distance has only magnitude, while displacement has both magnitude and direction.
- Distance is always equal to or greater than displacement.
- Explain scalar and vector quantities with examples.
Answer:
Scalar quantities are physical quantities that have only magnitude, not direction.
Examples: mass, distance, speed, energy.
Vector quantities are those which have both magnitude and direction.
Examples: displacement, velocity, acceleration, force.
- Differentiate between speed and velocity.
Answer:
Speed is the rate of change of distance with respect to time. It is a scalar quantity and has no direction.
Velocity is the rate of change of displacement with respect to time. It is a vector quantity and includes direction.
Key differences:
- Speed can never be negative, while velocity can be positive, negative, or zero.
- Speed is based on total path; velocity is based on net displacement.
- Explain different types of speed.
Answer:
There are three main types of speed:
- Uniform Speed: Equal distance in equal intervals of time.
- Non-uniform Speed: Unequal distances in equal intervals of time.
- Instantaneous Speed: Speed at a particular instant, measured by instruments like a speedometer.
- Define average speed and average velocity. Write their formulas.
Answer:
Average speed = Total distance / Total time
Average velocity = Total displacement / Total time
These are used when motion is not uniform or involves multiple segments.
- What is uniform acceleration? Give examples.
Answer:
Uniform acceleration occurs when a body’s velocity changes by equal amounts in equal intervals of time.
Example 1: A freely falling object under gravity.
Example 2: A car accelerating at a constant rate on a straight road.
- What is acceleration? Write its unit and formula.
Answer:
Acceleration is the rate of change of velocity per unit time.
Formula: a = (v – u)/t
Where,
v = final velocity,
u = initial velocity,
t = time taken.
SI Unit: metre/second² (m/s²)
- What do you mean by retardation? Give two examples.
Answer:
Retardation or negative acceleration occurs when velocity of a body decreases with time.
Example 1: A car slowing down at a traffic signal.
Example 2: A ball thrown upward against gravity.
- Explain with a graph how displacement-time graph indicates rest.
Answer:
When a body is at rest, it does not change its position with time.
In a displacement-time graph, this is shown by a horizontal straight line, indicating no change in displacement.
- Explain the nature of a displacement-time graph for uniform motion.
Answer:
In uniform motion, the body covers equal displacement in equal time intervals.
So, the graph is a straight line inclined to the time axis, with constant slope indicating constant velocity.
- What does the slope of displacement-time graph represent?
Answer:
The slope of a displacement-time graph represents the velocity of the body.
A steeper slope means higher velocity. Zero slope indicates the body is at rest.
- What does the slope of velocity-time graph represent?
Answer:
The slope of a velocity-time graph gives the acceleration of the body.
A straight line with positive slope shows uniform acceleration, while a negative slope indicates retardation.
- What does the area under velocity-time graph represent?
Answer:
The area under a velocity-time graph represents the displacement covered by the body.
For uniform motion, it is a rectangle; for uniformly accelerated motion, it is a triangle or trapezium.
- What is motion in one dimension? Give two examples.
Answer:
Motion in one dimension occurs when a body moves along a straight line in a single direction.
Example 1: A train moving on a straight track.
Example 2: An object falling vertically downward.
- Explain the three equations of motion.
Answer:
- v = u + at → final velocity
- s = ut + ½at² → displacement
- v² = u² + 2as → velocity-displacement relation
These apply only for motion with uniform acceleration.
- Define instantaneous velocity. How is it measured?
Answer:
Instantaneous velocity is the velocity of a body at a specific instant.
It is measured using the slope of the displacement-time graph at that instant or by using a speedometer in real life (for speed).
- Can average velocity be zero? Explain with an example.
Answer:
Yes, when total displacement is zero.
Example: A person walks 10 m north and returns 10 m south. Total displacement = 0, so average velocity = 0.
- Write differences between displacement and distance.
Answer:
- Displacement is vector; distance is scalar.
- Displacement can be zero/negative; distance is always positive.
- Displacement is the shortest path; distance is the actual path travelled.
- What do you mean by one-dimensional motion?
Answer:
One-dimensional motion refers to movement along a straight line in one direction only, such as along the x-axis.
- Give an example when speed is constant but velocity changes.
Answer:
When a body moves in a circular path at constant speed, its velocity changes due to change in direction.
- What is free fall? What is the acceleration involved?
Answer:
Free fall is motion of a body under the influence of gravity alone.
It experiences acceleration due to gravity, approximately 9.8 m/s².
- What is the direction of acceleration due to gravity?
Answer:
The direction of acceleration due to gravity is always vertically downward toward the center of the Earth.
- Why is displacement zero in a round trip?
Answer:
Because the initial and final positions are the same, so the shortest distance (displacement) is zero.
- How does velocity-time graph help in calculating displacement?
Answer:
The area under the velocity-time graph represents displacement; for uniform motion it’s a rectangle, and for acceleration it’s a trapezium.
- Define and derive the first equation of motion.
Answer:
v = u + at
Start from: a = (v – u)/t
Rearranging: v = u + at
Where, u = initial velocity, a = acceleration, t = time
- Derive the second equation of motion using algebra.
Answer:
s = ut + ½at²
Distance = Average velocity × Time
= (u + v)/2 × t
Replace v with (u + at):
s = (u + u + at)/2 × t = (2u + at)/2 × t = ut + ½at²
- Derive the third equation of motion.
Answer:
v² = u² + 2as
From a = (v² – u²)/(2s), rearranged gives:
v² = u² + 2as
- Give two conditions where displacement is zero but distance is not.
Answer:
- A person walks 5 m forward and 5 m back.
- A car completes a circular lap and returns to the start.
- Write the characteristics of uniform motion.
Answer:
- Equal distance in equal time intervals.
- Zero acceleration.
- Displacement-time graph is a straight inclined line.
- Write the characteristics of non-uniform motion.
Answer:
- Unequal distances in equal intervals.
- Changing speed or direction.
- Displacement-time graph is a curve.
- Write the features of velocity-time graph for uniformly accelerated motion.
Answer:
- Straight line inclined to time axis.
- Slope gives acceleration.
- Area under graph gives displacement.
- Give the differences between uniform and non-uniform acceleration.
Answer:
Uniform Acceleration: Constant change in velocity.
Non-Uniform Acceleration: Irregular change in velocity.
- What is the difference between scalar and vector quantities?
Answer:
Scalar: Only magnitude (e.g., speed, distance)
Vector: Magnitude + direction (e.g., velocity, displacement)
- State whether acceleration can be zero during motion.
Answer:
Yes, in uniform motion, velocity remains constant and acceleration is zero.
- Why is velocity-time graph preferred over speed-time graph in physics?
Answer:
Because velocity includes direction and is a vector, it gives a more complete picture of motion.
- Give two examples each of scalar and vector quantities.
Answer:
Scalars: Mass, Speed
Vectors: Displacement, Force
- How does one identify retardation from a graph?
Answer:
In a velocity-time graph, a negative slope (line going down) indicates retardation.
- What is the use of a speedometer and odometer in vehicles?
Answer:
Speedometer measures instantaneous speed, and odometer measures total distance covered.
- What is the difference between average and instantaneous speed?
Answer:
Average Speed: Total distance / Total time
Instantaneous Speed: Speed at a specific instant
- What is meant by rest in physics?
Answer:
A body is said to be at rest if it does not change its position with respect to its surroundings over time.
- Why is displacement a vector quantity while distance is scalar?
Answer:
Displacement has both magnitude and direction because it measures the shortest path between two points in a specific direction.
Distance only measures the actual length of the path travelled, irrespective of direction, making it a scalar.
- A car moves 60 km north and then 40 km south. Calculate the total distance and displacement.
Answer:
Distance: 60 km + 40 km = 100 km
Displacement: 60 km – 40 km = 20 km towards north
Hence, the total distance is 100 km and displacement is 20 km north.
- A body is thrown upward. Describe the motion during upward and downward journey.
Answer:
Upward motion: The body moves against gravity, velocity decreases due to retardation (−9.8 m/s²).
At highest point: Velocity becomes zero.
Downward motion: The body accelerates downward with +9.8 m/s² due to gravity. The motion is symmetric if air resistance is neglected.
- What is the difference between instantaneous and average velocity?
Answer:
Instantaneous Velocity: Velocity at a specific moment of time; measured using speedometer or graph slope.
Average Velocity: Total displacement divided by total time; used when motion is non-uniform or segmented.
- Explain motion under gravity using velocity-time graph.
Answer:
For free fall, velocity-time graph is a straight line sloping upwards from the origin, showing increasing velocity.
For upward motion, the graph is a straight line sloping downward, indicating decreasing velocity until it reaches zero.
- What are the conditions for using equations of motion?
Answer:
- The motion must be in a straight line (one dimension).
- Acceleration must be uniform (constant).
- Initial velocity, time, or final velocity must be known.
Without these, the equations cannot be applied reliably.
- A ball is dropped from a height. Describe the nature of its acceleration, velocity, and displacement.
Answer:
As the ball falls, it accelerates downward due to gravity (g = 9.8 m/s²).
Its velocity increases linearly with time.
Displacement increases in the downward direction.
The motion is uniformly accelerated.
- Can a body have zero velocity but non-zero acceleration? Explain with an example.
Answer:
Yes. Example: A body thrown vertically upward has zero velocity at the highest point but continues to accelerate downward due to gravity.
So, velocity = 0 but acceleration = 9.8 m/s² downward.
- What are the key differences between motion at constant speed and motion at constant velocity?
Answer:
- Constant speed: Magnitude of speed remains the same, direction may change.
- Constant velocity: Both magnitude and direction remain unchanged.
Thus, an object moving in a circle at constant speed doesn’t have constant velocity.
- A vehicle accelerates from rest at 2 m/s² for 10 seconds. Find final velocity and displacement.
Answer:
Given: u = 0, a = 2 m/s², t = 10 s
Final velocity (v): v = u + at = 0 + 2 × 10 = 20 m/s
Displacement (s): s = ut + ½at² = 0 + ½ × 2 × 100 = 100 m
Hence, final velocity = 20 m/s and displacement = 100 m.
Give Reasons
- Distance is always positive.
Answer: Because it is the total path length covered by a body and does not consider direction.
- Displacement can be zero even when distance is not.
Answer: Because displacement depends on the net change in position, which can be zero if the body returns to its starting point.
- Velocity can be negative.
Answer: Because velocity is a vector quantity and takes direction into account.
- Speed can never be negative.
Answer: Because speed is a scalar quantity and does not involve direction.
- A body is said to be in motion even when speed is zero momentarily.
Answer: Because motion is defined by change in position over time, not just speed at a particular instant.
- A body at rest has zero velocity.
Answer: Because there is no change in position with time.
- Acceleration is a vector quantity.
Answer: Because it has both magnitude and direction.
- A car moving with constant speed may still be accelerating.
Answer: Because a change in direction causes a change in velocity, hence acceleration.
- A body moving with uniform speed has zero acceleration.
Answer: Because its velocity (speed with direction) is constant over time.
- Velocity is more informative than speed.
Answer: Because velocity includes direction, whereas speed does not.
- A body thrown vertically upward has acceleration even at the highest point.
Answer: Because acceleration due to gravity always acts downward throughout the motion.
- Displacement can be negative.
Answer: Because it depends on the direction of motion relative to the reference point.
- The area under a velocity-time graph gives displacement.
Answer: Because velocity × time = displacement, and the graph’s area represents this product.
- The slope of a velocity-time graph gives acceleration.
Answer: Because acceleration is defined as the rate of change of velocity with time.
- The slope of a displacement-time graph gives velocity.
Answer: Because velocity is the rate of change of displacement with respect to time.
- The SI unit of acceleration is m/s².
Answer: Because it represents the change in velocity (m/s) per unit time (s).
- A straight line in a velocity-time graph shows uniform acceleration.
Answer: Because the velocity changes at a constant rate over time.
- The displacement of a body can be zero even when motion has taken place.
Answer: Because if the body returns to its starting point, initial and final positions are the same.
- Retardation is also called negative acceleration.
Answer: Because it reduces the velocity of the moving body.
- A horizontal line in a displacement-time graph indicates rest.
Answer: Because there is no change in displacement with respect to time.
- Average speed is always greater than or equal to average velocity.
Answer: Because total distance is always greater than or equal to total displacement.
- A car going in a circular track at constant speed has changing velocity.
Answer: Because the direction is continuously changing, affecting velocity.
- A body under free fall experiences acceleration.
Answer: Because of the gravitational pull of the Earth, which causes velocity to increase.
- A body with zero velocity can still have acceleration.
Answer: Because acceleration is change in velocity, and it can exist even when velocity is momentarily zero.
- Displacement is always less than or equal to distance.
Answer: Because displacement is the shortest straight-line path, while distance is the actual path travelled.
- The value of ‘g’ is taken as 9.8 m/s² near Earth’s surface.
Answer: Because it’s the standard acceleration due to Earth’s gravity.
- Velocity-time graph helps calculate acceleration.
Answer: Because the slope of the graph directly gives acceleration.
- In uniform acceleration, the velocity changes equally in equal intervals.
Answer: Because the rate of change of velocity is constant.
- Velocity is a vector but speed is not.
Answer: Because velocity includes both magnitude and direction, unlike speed.
- Instantaneous speed is measured using a speedometer.
Answer: Because it shows the speed of the vehicle at that particular instant.
- Average velocity can be zero even when average speed is not.
Answer: Because if displacement is zero, average velocity is zero, but distance (and hence average speed) is not.
- Odometer cannot measure displacement.
Answer: Because it records total distance travelled, irrespective of direction.
- A car decelerating shows negative acceleration.
Answer: Because its velocity is decreasing with time.
- The direction of acceleration due to gravity is always downward.
Answer: Because gravity pulls objects toward the center of the Earth.
- The second equation of motion includes both velocity and acceleration.
Answer: Because it calculates displacement when both are acting over time.
- Velocity-time graph of an object at rest is a horizontal line on the time axis.
Answer: Because its velocity is zero throughout the time.
- A body moving with variable speed has a curved displacement-time graph.
Answer: Because its slope (velocity) is not constant.
- The displacement-time graph of a body with constant velocity is a straight line.
Answer: Because displacement increases linearly with time.
- A body thrown upwards comes down due to gravity.
Answer: Because gravity acts downward and opposes upward motion, eventually reversing it.
- Speed does not determine direction of motion.
Answer: Because speed is a scalar and lacks directional information.
- Acceleration-time graph of uniform acceleration is a straight line parallel to the time axis.
Answer: Because the value of acceleration remains constant over time.
- A car moving in a straight line can have negative velocity.
Answer: Because velocity depends on direction; movement opposite to the chosen direction gives negative value.
- The displacement of a body in circular motion for one complete round is zero.
Answer: Because the initial and final positions are the same.
- Average velocity is useful in analyzing non-uniform motion.
Answer: Because it provides an effective velocity over the total time interval.
- Retardation occurs when brakes are applied.
Answer: Because the velocity of the vehicle starts decreasing with time.
- Displacement is a better indicator of net motion than distance.
Answer: Because it gives the shortest path and direction from start to finish.
- A negative slope in a velocity-time graph indicates retardation.
Answer: Because velocity is decreasing with time.
- A body accelerating in one dimension has velocity and acceleration in the same line.
Answer: Because motion and change in velocity both occur along a single axis.
- If a body has positive velocity and negative acceleration, it is slowing down.
Answer: Because acceleration acts opposite to the direction of velocity.
- In uniform motion, distance-time graph is linear.
Answer: Because the body covers equal distances in equal time intervals.
Arrange the Words
Case Studies
Case Study 1:
A car moves 40 km north in 1 hour and then 30 km south in the next 1 hour.
Q1. What is the total distance travelled?
Q2. What is the total displacement?
Q3. What is the average speed?
Q4. What is the average velocity?
Answers:
- 70 km
- 10 km north
- 70 ÷ 2 = 35 km/h
- 10 ÷ 2 = 5 km/h north
Case Study 2:
An object starts from rest and accelerates uniformly at 2 m/s² for 5 seconds.
Q1. What is the final velocity?
Q2. What is the displacement?
Q3. Which equation of motion is used?
Answers:
- v = u + at = 0 + 2×5 = 10 m/s
- s = ut + ½at² = 0 + ½×2×25 = 25 m
- First and second equations of motion
Case Study 3:
A bus is moving with a uniform speed of 50 km/h. It stops at a signal for 10 minutes and resumes the same speed.
Q1. Is the motion uniform?
Q2. What is the speed during the stop?
Q3. What kind of speed is shown on the speedometer when moving?
Answers:
- No, because of interruption
- 0 km/h
- Instantaneous speed
Case Study 4:
A runner covers 100 m east, then 100 m west.
Q1. What is the total distance covered?
Q2. What is the total displacement?
Q3. Is the displacement zero? Why?
Answers:
- 200 m
- 0 m
- Yes, because the runner returns to the starting point
Case Study 5:
A body moves with a constant speed of 10 m/s for 10 seconds.
Q1. What is the total distance?
Q2. Is the motion accelerated?
Q3. What is the displacement if the direction is unchanged?
Answers:
- 10×10 = 100 m
- No, speed is constant
- 100 m
Case Study 6:
A motorcycle increases its velocity from 20 m/s to 40 m/s in 4 seconds.
Q1. What is its acceleration?
Q2. What is the displacement during this time?
Q3. Which formula is used for (2)?
Answers:
- a = (v – u)/t = (40 – 20)/4 = 5 m/s²
- s = ut + ½at² = 20×4 + ½×5×16 = 80 + 40 = 120 m
- Second equation of motion
Case Study 7:
A car moves with uniform acceleration and its velocity-time graph is a straight line sloping upwards.
Q1. What does the slope indicate?
Q2. What is the shape of the displacement-time graph?
Q3. What type of acceleration is shown?
Answers:
- Constant acceleration
- Parabola (curved line)
- Uniform acceleration
Case Study 8:
A body falls freely from a height.
Q1. What is its acceleration?
Q2. Which physical quantity increases linearly?
Q3. What is the value of ‘g’?
Answers:
- 9.8 m/s²
- Velocity
- g = 9.8 m/s²
Case Study 9:
A train moves with a uniform velocity of 60 km/h.
Q1. What is its acceleration?
Q2. What does its velocity-time graph look like?
Q3. Can it have zero displacement?
Answers:
- 0 (uniform velocity)
- Horizontal line parallel to time axis
- Only if it returns to starting point
Case Study 10:
A body moves 5 m east, then 3 m west.
Q1. What is the total distance?
Q2. What is the net displacement?
Q3. Is distance > displacement?
Answers:
- 8 m
- 2 m east
- Yes
Case Study 11:
An athlete runs a circular track of radius 70 m and returns to the starting point.
Q1. What is the displacement?
Q2. What is the distance?
Q3. Why is displacement zero?
Answers:
- 0 m
- 2πr = 2×3.14×70 = 439.6 m
- Start and end points are same
Case Study 12:
A car moves with velocity 30 m/s and takes 10 seconds to stop.
Q1. What is the acceleration?
Q2. What kind of acceleration is it?
Q3. What is the displacement?
Answers:
- a = (0 – 30)/10 = –3 m/s²
- Retardation
- s = ut + ½at² = 30×10 + ½×(–3)×100 = 300 – 150 = 150 m
Case Study 13:
A stone is thrown vertically upward with velocity 20 m/s.
Q1. What is its velocity at highest point?
Q2. What is acceleration at the highest point?
Q3. Is it in motion at the highest point?
Answers:
- 0 m/s
- –9.8 m/s²
- Yes, though momentarily at rest
Case Study 14:
A student jogs 500 m in 5 minutes.
Q1. What is her average speed in m/s?
Q2. Convert it to km/h.
Q3. Is the motion uniform if speed varies each minute?
Answers:
- 500 ÷ 300 = 1.67 m/s
- 1.67 × 3.6 = 6 km/h
- No, if speed varies
Case Study 15:
A bullet moves through air and slows down due to resistance.
Q1. What kind of acceleration is this?
Q2. Will speed increase or decrease?
Q3. Is it uniform or variable acceleration?
Answers:
- Retardation
- Decrease
- Variable
Case Study 16:
An object moves with 0 m/s² acceleration.
Q1. What is its velocity like?
Q2. Is the object speeding up?
Q3. What kind of motion is this?
Answers:
- Constant velocity
- No
- Uniform motion
Case Study 17:
A truck moves 100 m in 10 seconds, then 50 m in 10 seconds.
Q1. What is the type of motion?
Q2. What are speeds in each case?
Q3. Is the motion uniform?
Answers:
- Non-uniform
- 10 m/s and 5 m/s
- No
Case Study 18:
A boy throws a ball upwards.
Q1. What force acts after release?
Q2. What is acceleration throughout motion?
Q3. What happens to velocity on the way up?
Answers:
- Gravity
- –9.8 m/s²
- Decreases to 0
Case Study 19:
A body moves with uniform acceleration.
Q1. What are the equations applicable?
Q2. What is the nature of v-t graph?
Q3. How to find displacement from v-t graph?
Answers:
- v = u + at, s = ut + ½at², v² = u² + 2as
- Straight line
- Area under graph
Case Study 20:
Two cars A and B travel same distance, A with uniform speed, B with acceleration.
Q1. Who takes less time?
Q2. Whose motion is easier to analyze?
Q3. Which graph for B is curved?
Answers:
- Depends on values, likely B if accelerating
- A
- Displacement-time graph
Numericals
- A body travels 100 m in 20 seconds. Find its speed.
Answer: Speed = 100 ÷ 20 = 5 m/s
- A car moves with a uniform speed of 60 km/h for 2 hours. Find the distance covered.
Answer: Distance = 60 × 2 = 120 km
- A train covers 180 km in 3 hours. What is its average speed?
Answer: Average speed = 180 ÷ 3 = 60 km/h
- A bike starts from rest and accelerates uniformly at 3 m/s² for 5 seconds. Find its final velocity.
Answer: v = u + at = 0 + 3 × 5 = 15 m/s
- A body is moving with an initial velocity of 10 m/s and acceleration of 2 m/s². Find its velocity after 4 seconds.
Answer: v = u + at = 10 + 2 × 4 = 18 m/s
- A scooter moves with a velocity of 20 m/s for 30 seconds. Calculate the distance covered.
Answer: Distance = velocity × time = 20 × 30 = 600 m
- A train starting from rest attains a speed of 72 km/h in 5 minutes. Find its acceleration in m/s².
Answer:
72 km/h = 20 m/s
a = (v – u) / t = (20 – 0) / (5 × 60) = 20 / 300 = 0.0667 m/s²
- A car moves with a velocity of 25 m/s. How far will it travel in 10 seconds?
Answer: Distance = 25 × 10 = 250 m
- A body moves 20 m in 4 s and then 40 m in 2 s. Find its average speed.
Answer: Total distance = 60 m, Total time = 6 s
Average speed = 60 ÷ 6 = 10 m/s
- A ball falls freely for 3 s. Find the distance it covers. (g = 9.8 m/s²)
Answer: s = ½gt² = ½ × 9.8 × 9 = 44.1 m
- A stone is thrown vertically upward with a velocity of 30 m/s. How high will it go?
Answer: v² = u² + 2as ⇒ 0 = 900 – 2 × 9.8 × s
s = 900 / (2 × 9.8) = 45.92 m
- A body accelerates from 5 m/s to 20 m/s in 3 seconds. Find the acceleration.
Answer: a = (v – u) / t = (20 – 5) / 3 = 5 m/s²
- Find the distance travelled during acceleration in the above case.
Answer: s = ut + ½at² = 5 × 3 + ½ × 5 × 9 = 15 + 22.5 = 37.5 m
- A train moves with a constant acceleration of 0.5 m/s² for 10 seconds. Find final velocity if it started from rest.
Answer: v = u + at = 0 + 0.5 × 10 = 5 m/s
- A bus slows down from 15 m/s to 5 m/s in 5 seconds. Find its acceleration.
Answer: a = (5 – 15)/5 = -2 m/s²
- A body is moving with a velocity of 30 m/s and decelerates at 3 m/s². How long will it take to come to rest?
Answer: v = u + at ⇒ 0 = 30 + (–3)t ⇒ t = 10 s
- A cyclist covers a distance of 2 km in 5 minutes. Find his speed in m/s.
Answer: Speed = 2000 ÷ 300 = 6.67 m/s
- A ball is thrown up with 19.6 m/s. Find the time to reach the highest point.
Answer: v = u – gt ⇒ 0 = 19.6 – 9.8t ⇒ t = 2 s
- Find the maximum height in the above case.
Answer: s = ut – ½gt² = 19.6 × 2 – ½ × 9.8 × 4 = 39.2 – 19.6 = 19.6 m
- A train accelerates from rest to 36 km/h in 20 s. Find acceleration.
Answer: 36 km/h = 10 m/s ⇒ a = (10 – 0)/20 = 0.5 m/s²
- A truck covers 150 m in 10 s and then 250 m in 20 s. Find average speed.
Answer: Total distance = 400 m; Total time = 30 s
Average speed = 400 ÷ 30 = 13.33 m/s
- A runner covers first 100 m in 10 s and next 100 m in 20 s. Find average speed.
Answer: Total distance = 200 m; Total time = 30 s
Average speed = 6.67 m/s
- A car travels 30 km in 1 h and 60 km in 2 h. Find average speed.
Answer: Total distance = 90 km; Total time = 3 h
Average speed = 30 km/h
- A rocket moves with acceleration 20 m/s² for 4 seconds. Find final velocity.
Answer: v = 0 + 20 × 4 = 80 m/s
- What distance does the rocket cover in that time?
Answer: s = ½at² = ½ × 20 × 16 = 160 m
- A ball dropped from a building takes 3 seconds to reach ground. Find height.
Answer: s = ½gt² = 0.5 × 9.8 × 9 = 44.1 m
- A stone is thrown upward and comes down in 6 seconds. Find max height.
Answer: Time up = 3 s ⇒ s = 0.5 × 9.8 × 9 = 44.1 m
- A body starts from rest, accelerates uniformly at 4 m/s² for 5 s. Find displacement.
Answer: s = ½at² = 0.5 × 4 × 25 = 50 m
- A car starts from rest and covers 100 m in 5 s. Find acceleration.
Answer: s = ut + ½at² ⇒ 100 = 0 + 0.5a × 25 ⇒ a = 8 m/s²
- A car moving at 15 m/s is brought to rest in 5 s. Find retardation.
Answer: a = (0 – 15)/5 = –3 m/s²
- A train slows down uniformly from 54 km/h to rest in 10 s. Find distance covered.
Answer: u = 15 m/s, v = 0, t = 10
s = (u + v)/2 × t = (15 + 0)/2 × 10 = 75 m
- A car moves with a uniform velocity of 12 m/s. How much distance in 7 seconds?
Answer: Distance = 12 × 7 = 84 m
- A bus covers 480 m in 40 seconds. Find its speed.
Answer: Speed = 480 ÷ 40 = 12 m/s
- A body falls freely for 5 seconds. Find final velocity.
Answer: v = gt = 9.8 × 5 = 49 m/s
- Find distance fallen in the above case.
Answer: s = ½gt² = 0.5 × 9.8 × 25 = 122.5 m
- A car moves at 60 km/h for 30 minutes. Find distance.
Answer: Distance = 60 × 0.5 = 30 km
- A body decelerates at 2 m/s² from 20 m/s to rest. Find time taken.
Answer: t = (0 – 20)/-2 = 10 s
- A ball thrown up takes 2.5 s to reach top. Find initial velocity.
Answer: v = u – gt ⇒ 0 = u – 9.8 × 2.5 ⇒ u = 24.5 m/s
- Find height reached in above problem.
Answer: s = u² / 2g = (24.5)² / (2 × 9.8) = 30.6 m
- A particle moves with constant acceleration 3 m/s² for 6 seconds. Find displacement.
Answer: s = ½at² = 0.5 × 3 × 36 = 54 m
- A body accelerates from 10 m/s to 40 m/s in 3 seconds. Find acceleration.
Answer: a = (40 – 10)/3 = 10 m/s²
- A car travels at 20 m/s for 15 s, then stops. Find total distance.
Answer: Distance = 20 × 15 = 300 m
- A car travels 60 km north and 40 km south. Find displacement.
Answer: Displacement = 60 – 40 = 20 km north
- A body accelerates uniformly for 8 s and travels 128 m. Acceleration = 4 m/s². Find initial velocity.
Answer: s = ut + ½at² ⇒ 128 = 8u + 0.5 × 4 × 64
128 = 8u + 128 ⇒ u = 0 m/s
- A car covers 500 m in 50 s. Find speed.
Answer: Speed = 500 ÷ 50 = 10 m/s
- A falling object gains 29.4 m/s speed in 3 s. Find g.
Answer: g = v / t = 29.4 / 3 = 9.8 m/s²
- A bus moving at 72 km/h slows down to rest in 10 seconds. Find retardation.
Answer: 72 km/h = 20 m/s ⇒ a = (0 – 20)/10 = –2 m/s²
- A car slows from 30 m/s to 10 m/s in 4 seconds. Find distance covered.
Answer: s = (u + v)/2 × t = (30 + 10)/2 × 4 = 80 m
- An object thrown vertically takes 4 s to reach the ground. Find height.
Answer: s = ½gt² = 0.5 × 9.8 × 16 = 78.4 m
A body moves 10 m north, then 10 m south. Find total distance and displacement.
Answer: Distance = 10 + 10 = 20 m; Displacement = 0 m
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