HARD
AS and A Level
IMPORTANT
Earn 100

A ball is thrown towards a wall, which is 5 m away, at 2.25 m s-1. It slows down at a constant rate of 0.2 m s-2 until it strikes the wall. It bounces back at 80% of the speed it struck the wall originally. It again slows down at a constant rate of 0.2 m s-2 until coming to rest. Sketch a velocity-time graph and a displacement-time graph for the motion, measuring displacement from the wall, taking the direction away from the wall as positive.

Important Questions on Velocity and Acceleration

HARD
AS and A Level
IMPORTANT

A billiard ball is on the centre spot of a 6 m long table and is struck towards one of the cushions with initial speed 3.1 m s-1. It slows on the table at 0.2 m s-2. When it bounces of the cushion its speed reduces to 70% of the speed with which it struck the cushion. The ball is left until it comes to rest.

Sketch the velocity-time and displacement-time graphs for the ball, taking the centre of the table as the origin for displacement and the original direction of motion as positive.

HARD
AS and A Level
IMPORTANT

A billiard ball is on the centre spot of a 6 m long table and is struck towards one of the cushions with initial speed 3.1 m s-1. It slows on the table at 0.2 m s-2. When it bounces of the cushion its speed reduces to 70% of the speed with which it struck the cushion. The ball is left until it comes to rest.

What assumptions have been made in your answer?

HARD
AS and A Level
IMPORTANT
A ball is released from rest 20 m above the ground and accelerates under gravity at 10 m s-2. When it bounces its speed halves. If bounce n occurs at time tn the speed after the bounce is vn. Show that vn=15-2.5tn and deduce that, despite infinitely many bounces, the ball stops bouncing after 6 s.
EASY
AS and A Level
IMPORTANT

A man and his young son play a game. The man rolls a ball along the ground. His son runs after the ball to fetch it.

The ball starts rolling at 10 m s-1 but decelerates at a constant rate of 2 m s-2. Find the distance covered when it comes to rest.

HARD
AS and A Level
IMPORTANT

A man and his young son play a game. The man rolls a ball along the ground. His son runs after the ball to fetch it.

Once the ball has stopped, the boy runs to fetch it. He starts from rest beside his father and accelerates at a constant rate of 2 m s-2 for 3 s before maintaining a constant speed. Find the time taken to reach the ball.

HARD
AS and A Level
IMPORTANT

A car is travelling at 15 m s-1 when the speed limit increases and the car accelerates at a constant rate of 3 m s-2 until reaching a top speed of 30 m s-1.

Find the distance covered until reaching top speed.

HARD
AS and A Level
IMPORTANT

A car is travelling at 15 m s-1 when the speed limit increases and the car accelerates at a constant rate of 3 m s-2 until reaching a top speed of 30 m s-1.

Once the car is at top speed, there is a set of traffic lights 600 m away. The car maintains 30 m s-1 until it starts to decelerate at a constant rate of 5 m s-2 to come to rest at the lights. Find the time taken from reaching top speed until it comes to rest at the traffic lights.

HARD
AS and A Level
IMPORTANT

In a race, the lead runner is 60 m ahead of the chaser with 200 m to go and is running at 4 m s-1. The chaser is running at 5 m s-1.

Find the minimum constant acceleration required by the chaser to catch the lead runner.