Acceleration

13* Two students run for 10 seconds.

The graph shows their motion.

Compare the motion of Student A and Student B.

Include acceleration and distance travelled.

The graph shows how acceleration changes with the mass of a car.

Use the graph to determine the acceleration of a car with a mass of 1250 kg.

Acceleration =........ m / s²

Use the graph to estimate the acceleration of a car with a mass of 700 kg.

Acceleration =........ m / s²

A car is travelling at 60 mph.

Which statement most likely describes what the car is doing?

Tick (✓) one box.

This graph shows how the velocity of a car changes when driver A sees a hazard in the road at time = 0 seconds.

Describe how the graph shows that the reaction time of driver A is 0.6 s.

Calculate the braking distance on the graph.

Driver B then drives the same car with the same road conditions and sees the same hazard.

Driver B:

• drives at the same speed as driver A

• has been drinking alcohol

• applies the brakes harder than driver A.

Draw another line on the graph to show how the velocity changes for driver B.

A student drops a ball onto a hard floor. The mass of the ball is 0.06 kg.

The ball bounces once and the student catches the ball.

The graph shows how the velocity of the ball changes after it is dropped.

State a point on the graph where the gravitational store of the ball has a minimum value.

Choose from A, B, C, D or E.

State the point on the graph where the kinetic store of the ball has a maximum value.

Choose from A, B, C, D or E.

Calculate the kinetic energy of the ball at 0.4 seconds. Use the Data Sheet.

Calculate the potential energy of the ball at A.

Use the graph and the equation: potential energy = mass × height × gravitational field strength

Gravitational field strength = 10 N / kg.

The potential energy of the ball at E is 0.45 J.

Calculate the efficiency of the ball bounce. Use the Data Sheet and your answer to (c)(i).

A car accelerates from rest. This is a graph of the motion of the car on a straight road.

In the first 20 seconds, the car travels 750 m.

Show that the total distance travelled in 40 seconds is approximately 2000 m.

Use the graph to help you.

Calculate the average speed for the total journey shown in the graph.

Average speed =........ m / s

Look at the graph below.

Which of the following is the distance travelled between 0 and 6 seconds?

A 22.5 m

B 45.0 m

C 67.5 m

D 90.0 m

13* Person A and person B drive their cars along the same road on different days.

Both cars travel at 25 m / s. The traffic lights along the road change to red.

Person A and person B see the red light and press the brakes in their car.

The graphs show the velocity of each car after person A and person B see the red light.

The graphs are drawn using the same scale.

Explain what the graphs show you about how the cars stop.

Use values from the graphs and calculations in your answer.