20-Second Physics Challenge
Trigger Recognition & Trap Elimination
A ball is projected vertically upward with a speed of 30 m/s. Taking g = 10 m/s², its velocity after 2 s is
Trigger
Velocity after given time
Formula
Execution
A ball is projected vertically upward with a speed of 20 m/s. The height reached after 1 s is
Trigger
Height after given time
Formula
Execution
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?
Trigger
Same height recognition
Concept
Execution
A stone is dropped from rest. Taking g = 10 m/s², its speed after 4 s is
Trigger
Free fall from rest
Formula
Execution
A stone is dropped from a tower and reaches the ground in 3 s. The height of the tower is
Trigger
Tower drop
Formula
Execution
A ball is thrown vertically downward from a tower with a speed of 10 m/s. Its velocity after 2 s is
Trigger
Downward projection
Formula
Execution
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
Trigger
Projection from tower
Concept
A freely falling body covers distances in successive seconds in the ratio
Trigger
Successive-second motion
Concept
Execution
A body is dropped from rest. The distance covered during the second second is
Trigger
Distance during nth second
Formula
Execution
A body falls freely for 4 s. The distance covered during the last second is
Trigger
Last-second motion
Formula
Execution
Ignoring air resistance, a heavy stone and a light stone are dropped together. Which reaches the ground first?
Trigger
Mass dependence question
Concept
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
Trigger
Delayed release
Formula
Execution
Balls are projected vertically upward at intervals of 2 seconds. For successive balls to meet, the minimum launch speed must be
Concept
Execution
Taking upward as positive, the value of acceleration due to gravity is
Trigger
Sign Convention
Concept
Execution
A ball is projected vertically upward with a speed of 40 m/s. Taking g = 10 m/s², its total time of flight is
Trigger
Time of Flight
Formula
Execution
A ball is projected vertically upward. At half of its maximum height, its acceleration is
Concept
Execution
At the highest point of vertical motion, which quantity becomes zero?
Concept
Execution
A body is projected vertically upward. Which graph correctly represents its acceleration versus time?
Trigger
Graph Recognition
Concept
Execution
A ball is projected upward. Which quantity continuously decreases during the upward journey?
Concept
Execution
A body is dropped from rest. Its velocity-time graph is
Trigger
Graph Intelligence
Formula
Execution
For a body moving only under gravity, the acceleration-time graph is
Concept
Execution
A stone is projected vertically upward with a speed of 40 m/s. The time taken to reach the highest point is
Trigger
Highest point
Formula
Execution
A ball is projected vertically upward with a speed of 20 m/s. The maximum height reached is
Trigger
Maximum height
Formula
Execution
At the highest point of its motion, a vertically projected ball has
Trigger
Highest point state
Key Concept
A ball is projected vertically upward with a speed of 30 m/s. Its speed when it returns to the point of projection is
Trigger
Return to launch point
Concept
Execution
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?
Trigger
Same height recognition
Concept
Execution
A stone is dropped from rest. Taking g = 10 m/s², its speed after 4 s is
Trigger
Free fall from rest
Formula
Execution
A stone is dropped from a tower and reaches the ground in 3 s. The height of the tower is
Trigger
Tower drop
Formula
Execution
A ball is thrown vertically downward from a tower with a speed of 10 m/s. Its velocity after 2 s is
Trigger
Downward projection
Formula
Execution
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
Trigger
Projection from tower
Concept
A freely falling body covers distances in successive seconds in the ratio
Trigger
Successive-second motion
Concept
Execution
A body is dropped from rest. The distance covered during the second second is
Trigger
Distance during nth second
Formula
Execution
A body falls freely for 4 s. The distance covered during the last second is
Trigger
Last-second motion
Formula
Execution
Ignoring air resistance, a heavy stone and a light stone are dropped together. Which reaches the ground first?
Trigger
Mass dependence question
Concept
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
Trigger
Delayed release
Formula
Execution
Balls are projected vertically upward at intervals of 2 seconds. For successive balls to meet, the minimum launch speed must be
Concept
Execution
Taking upward as positive, the value of acceleration due to gravity is
Trigger
Sign Convention
Concept
Execution
A ball is projected vertically upward with a speed of 40 m/s. Taking g = 10 m/s², its total time of flight is
Trigger
Time of Flight
Formula
Execution
A ball is projected vertically upward. At half of its maximum height, its acceleration is
Concept
Execution
At the highest point of vertical motion, which quantity becomes zero?
Concept
Execution
A body is projected vertically upward. Which graph correctly represents its acceleration versus time?
Trigger
Graph Recognition
Concept
Execution
A ball is projected upward. Which quantity continuously decreases during the upward journey?
Concept
Execution
A body is dropped from rest. Its velocity-time graph is
Trigger
Graph Intelligence
Formula
Execution
For a body moving only under gravity, the acceleration-time graph is
Concept
Execution