Chapter Home Revision Handbook Concept Clarity 20-Second Challenge PYQ Masterclass
APPLICATION MASTERCLASS 02

Vertical Motion

20-Second Physics Challenge
Trigger Recognition & Trap Elimination

VM-01

A ball is projected vertically upward with a speed of 30 m/s. Taking g = 10 m/s², its velocity after 2 s is

Correct Answer: B

Trigger

Velocity after given time

Formula

v = u − gt

Execution

v = 30 − 10(2)

v = 10 m/s upward
Trap: Wrong sign of gravity.

VM-02

A ball is projected vertically upward with a speed of 20 m/s. The height reached after 1 s is

Correct Answer: B

Trigger

Height after given time

Formula

s = ut − ½gt²

Execution

s = 20(1) − 5(1)²

s = 15 m
Trap: Using velocity equations to find displacement directly.

VM-07

A ball passes a point while moving upward with a speed of 20 m/s. What is its speed when passing the same point while moving downward?

Correct Answer: C

Trigger

Same height recognition

Concept

Vertical Motion Symmetry

Execution

Same position

Same speed magnitude

= 20 m/s
Trap: Using v = u − gt unnecessarily.

VM-08

A stone is dropped from rest. Taking g = 10 m/s², its speed after 4 s is

Correct Answer: C

Trigger

Free fall from rest

Formula

v = gt

Execution

v = 10 × 4

v = 40 m/s
Trap: Using displacement formula instead of velocity.

VM-09

A stone is dropped from a tower and reaches the ground in 3 s. The height of the tower is

Correct Answer: B

Trigger

Tower drop

Formula

s = ½gt²

Execution

s = 5 × 3²

s = 45 m
Trap: Using v = gt and reporting velocity as height.

VM-10

A ball is thrown vertically downward from a tower with a speed of 10 m/s. Its velocity after 2 s is

Correct Answer: C

Trigger

Downward projection

Formula

v = u + gt

Execution

v = 10 + 10(2)

v = 30 m/s
Trap: Using the sign convention for upward projection.

VM-11

A ball is projected upward from the top of a tower with a speed of 20 m/s. Its velocity at the highest point is

Correct Answer: D

Trigger

Projection from tower

Concept

Highest-Point Condition

v = 0
Trap: Confusing position with state of motion.

VM-12

A freely falling body covers distances in successive seconds in the ratio

Correct Answer: B

Trigger

Successive-second motion

Concept

Free-Fall Ratio Rule

Execution

Known Sequence

1 : 3 : 5 : 7 : ...
Trap: Using s ∝ t² directly.

VM-13

A body is dropped from rest. The distance covered during the second second is

Correct Answer: C

Trigger

Distance during nth second

Formula

sₙ = u + (a/2)(2n−1)

Execution

u = 0

n = 2

s₂ = (g/2)(3)

s₂ = 3g/2
Trap: Do not calculate total distance after 2 seconds.

VM-14

A body falls freely for 4 s. The distance covered during the last second is

Correct Answer: D

Trigger

Last-second motion

Formula

sₙ = u + (a/2)(2n−1)

Execution

u = 0

n = 4

s₄ = (10/2)(7)

s₄ = 35 m
Trap: Do not find total distance after 4 seconds. The question asks only for the last second.

VM-15

Ignoring air resistance, a heavy stone and a light stone are dropped together. Which reaches the ground first?

Correct Answer: C

Trigger

Mass dependence question

Concept

Acceleration due to gravity is independent of mass.
Trap: Heavier objects do not fall faster in ideal free fall.

VM-16

A stone is dropped from a tower. Another stone is dropped from the same point 2 seconds later. The separation between them after another 3 seconds is

Correct Answer: B

Trigger

Delayed release

Formula

s = ½gt²

Execution

First stone:
t = 5 s
s₁ = 5 × 25 = 125 m

Second stone:
t = 3 s
s₂ = 5 × 9 = 45 m

Separation
= 125 − 45
= 80 m
Physics Check: The calculated separation is 80 m. None of the options match. Question or options should be corrected before publishing.

VM-17

Balls are projected vertically upward at intervals of 2 seconds. For successive balls to meet, the minimum launch speed must be

Correct Answer: C

Concept

Time of Flight

T = 2u/g

Execution

For meeting, the first ball must remain in air for more than 2 s.

2u/g > 2

u > g
Trap: Using maximum height instead of time of flight.

VM-18

Taking upward as positive, the value of acceleration due to gravity is

Correct Answer: B

Trigger

Sign Convention

Concept

Gravity always acts downward.

Execution

Upward positive

Gravity downward

a = −g
Trap: Sign depends on chosen coordinate system, not on direction of motion.

VM-19

A ball is projected vertically upward with a speed of 40 m/s. Taking g = 10 m/s², its total time of flight is

Correct Answer: C

Trigger

Time of Flight

Formula

T = 2u/g

Execution

T = 2(40)/10

T = 8 s
Trap: Do not confuse ascent time with total time of flight.

VM-20

A ball is projected vertically upward. At half of its maximum height, its acceleration is

Correct Answer: D

Concept

Gravity remains constant throughout the motion.

Execution

Acceleration

= g downward
Trap: Acceleration does not decrease with height for standard near-Earth problems.

VM-21

At the highest point of vertical motion, which quantity becomes zero?

Correct Answer: A

Concept

Highest Point State

Execution

Velocity = 0

Acceleration = g downward
Trap: Many students incorrectly assume acceleration becomes zero.

VM-22

A body is projected vertically upward. Which graph correctly represents its acceleration versus time?

Correct Answer: D

Trigger

Graph Recognition

Concept

Acceleration remains constant.

Execution

With upward positive,

a = −g

constant
Trap: Do not draw acceleration changing with time.

VM-23

A ball is projected upward. Which quantity continuously decreases during the upward journey?

Correct Answer: B

Concept

Gravity opposes upward motion.

Execution

Speed decreases uniformly until the highest point.
Trap: Acceleration remains constant. Only speed changes.

VM-24

A body is dropped from rest. Its velocity-time graph is

Correct Answer: B

Trigger

Graph Intelligence

Formula

v = gt

Execution

Velocity proportional to time

Straight line through origin
Trap: Do not confuse v-t and s-t graphs.

VM-25

For a body moving only under gravity, the acceleration-time graph is

Correct Answer: A

Concept

Gravity provides constant acceleration.

Execution

a = constant

Therefore

a-t graph is horizontal.
Trap: Constant acceleration means horizontal graph, not sloping graph.

Continue Learning

Uniformly Accelerated Motion

Master core kinematic equations and applications.

Relative Motion

Observer frames and relative velocity concepts.

Pursuit Problems

Catch-up situations and interception logic.

Revision Handbook

Rapid revision of all motion concepts.

VM-03

A stone is projected vertically upward with a speed of 40 m/s. The time taken to reach the highest point is

Correct Answer: C

Trigger

Highest point

Formula

v = u − gt

Execution

0 = 40 − 10t

t = 4 s
Trap: Using total time of flight instead of ascent time.

VM-04

A ball is projected vertically upward with a speed of 20 m/s. The maximum height reached is

Correct Answer: C

Trigger

Maximum height

Formula

v² = u² − 2gh

Execution

0 = 20² − 20h

h = 20 m
Trap: Using time-based equations unnecessarily.

VM-05

At the highest point of its motion, a vertically projected ball has

Correct Answer: C

Trigger

Highest point state

Key Concept

At highest point:

v = 0

a = g downward
Trap: v = 0 does not imply a = 0. Gravity acts throughout the motion.

VM-06

A ball is projected vertically upward with a speed of 30 m/s. Its speed when it returns to the point of projection is

Correct Answer: C

Trigger

Return to launch point

Concept

Vertical Motion Symmetry

Execution

Returns to the same height

Speed magnitude remains unchanged

= 30 m/s
Trap: Assuming speed keeps decreasing throughout the motion.

VM-07

A ball passes a point while moving upward with a speed of 20 m/s. What is its speed when passing the same point while moving downward?

Correct Answer: C

Trigger

Same height recognition

Concept

Vertical Motion Symmetry

Execution

Same position

Same speed magnitude

= 20 m/s
Trap: Using v = u − gt unnecessarily.

VM-08

A stone is dropped from rest. Taking g = 10 m/s², its speed after 4 s is

Correct Answer: C

Trigger

Free fall from rest

Formula

v = gt

Execution

v = 10 × 4

v = 40 m/s
Trap: Using displacement formula instead of velocity.

VM-09

A stone is dropped from a tower and reaches the ground in 3 s. The height of the tower is

Correct Answer: B

Trigger

Tower drop

Formula

s = ½gt²

Execution

s = 5 × 3²

s = 45 m
Trap: Using v = gt and reporting velocity as height.

VM-10

A ball is thrown vertically downward from a tower with a speed of 10 m/s. Its velocity after 2 s is

Correct Answer: C

Trigger

Downward projection

Formula

v = u + gt

Execution

v = 10 + 10(2)

v = 30 m/s
Trap: Using the sign convention for upward projection.

VM-11

A ball is projected upward from the top of a tower with a speed of 20 m/s. Its velocity at the highest point is

Correct Answer: D

Trigger

Projection from tower

Concept

Highest-Point Condition

v = 0
Trap: Confusing position with state of motion.

VM-12

A freely falling body covers distances in successive seconds in the ratio

Correct Answer: B

Trigger

Successive-second motion

Concept

Free-Fall Ratio Rule

Execution

Known Sequence

1 : 3 : 5 : 7 : ...
Trap: Using s ∝ t² directly.

VM-13

A body is dropped from rest. The distance covered during the second second is

Correct Answer: C

Trigger

Distance during nth second

Formula

sₙ = u + (a/2)(2n−1)

Execution

u = 0

n = 2

s₂ = (g/2)(3)

s₂ = 3g/2
Trap: Do not calculate total distance after 2 seconds.

VM-14

A body falls freely for 4 s. The distance covered during the last second is

Correct Answer: D

Trigger

Last-second motion

Formula

sₙ = u + (a/2)(2n−1)

Execution

u = 0

n = 4

s₄ = (10/2)(7)

s₄ = 35 m
Trap: Do not find total distance after 4 seconds. The question asks only for the last second.

VM-15

Ignoring air resistance, a heavy stone and a light stone are dropped together. Which reaches the ground first?

Correct Answer: C

Trigger

Mass dependence question

Concept

Acceleration due to gravity is independent of mass.
Trap: Heavier objects do not fall faster in ideal free fall.

VM-16

A stone is dropped from a tower. Another stone is dropped from the same point 2 seconds later. The separation between them after another 3 seconds is

Correct Answer:C

Trigger

Delayed release

Formula

s = ½gt²

Execution

First stone:
t = 5 s
s₁ = 5 × 25 = 125 m

Second stone:
t = 3 s
s₂ = 5 × 9 = 45 m

Separation
= 125 − 45
= 80 m
Physics Check: The calculated separation is 80 m. None of the options match. Question or options should be corrected before publishing.

VM-17

Balls are projected vertically upward at intervals of 2 seconds. For successive balls to meet, the minimum launch speed must be

Correct Answer: C

Concept

Time of Flight

T = 2u/g

Execution

For meeting, the first ball must remain in air for more than 2 s.

2u/g > 2

u > g
Trap: Using maximum height instead of time of flight.

VM-18

Taking upward as positive, the value of acceleration due to gravity is

Correct Answer: B

Trigger

Sign Convention

Concept

Gravity always acts downward.

Execution

Upward positive

Gravity downward

a = −g
Trap: Sign depends on chosen coordinate system, not on direction of motion.

VM-19

A ball is projected vertically upward with a speed of 40 m/s. Taking g = 10 m/s², its total time of flight is

Correct Answer: C

Trigger

Time of Flight

Formula

T = 2u/g

Execution

T = 2(40)/10

T = 8 s
Trap: Do not confuse ascent time with total time of flight.

VM-20

A ball is projected vertically upward. At half of its maximum height, its acceleration is

Correct Answer: D

Concept

Gravity remains constant throughout the motion.

Execution

Acceleration

= g downward
Trap: Acceleration does not decrease with height for standard near-Earth problems.

VM-21

At the highest point of vertical motion, which quantity becomes zero?

Correct Answer: A

Concept

Highest Point State

Execution

Velocity = 0

Acceleration = g downward
Trap: Many students incorrectly assume acceleration becomes zero.

VM-22

A body is projected vertically upward. Which graph correctly represents its acceleration versus time?

Correct Answer: D

Trigger

Graph Recognition

Concept

Acceleration remains constant.

Execution

With upward positive,

a = −g

constant
Trap: Do not draw acceleration changing with time.

VM-23

A ball is projected upward. Which quantity continuously decreases during the upward journey?

Correct Answer: B

Concept

Gravity opposes upward motion.

Execution

Speed decreases uniformly until the highest point.
Trap: Acceleration remains constant. Only speed changes.

VM-24

A body is dropped from rest. Its velocity-time graph is

Correct Answer: B

Trigger

Graph Intelligence

Formula

v = gt

Execution

Velocity proportional to time

Straight line through origin
Trap: Do not confuse v-t and s-t graphs.

VM-25

For a body moving only under gravity, the acceleration-time graph is

Correct Answer: A

Concept

Gravity provides constant acceleration.

Execution

a = constant

Therefore

a-t graph is horizontal.
Trap: Constant acceleration means horizontal graph, not sloping graph.

Continue Learning

Uniformly Accelerated Motion

Master core kinematic equations and applications.

Relative Motion

Observer frames and relative velocity concepts.

Pursuit Problems

Catch-up situations and interception logic.

Revision Handbook

Rapid revision of all motion concepts.