Describing Motion (AQA GCSE Physics: Combined Science)

Some students take part in a 400-metre running race. 

They complete one lap of an athletics track shown in Figure 1, finishing at the point where they started.

Figure 1

One of the runners complete the lap in a time of 56 seconds.

Calculate the average speed of the runner. Give your answer to 2 significant figures.

At the end of the race their Physics teacher jokes that their average velocity was zero.

Explain whether their Physics teacher was correct.

A student starts at the starting line of the track and begins to run. They accelerate uniformly for 200 m.

Figure 2

Complete the distance-time graph in Figure 2 to show the motion of the student.

Halfway around the track, the student then comes to a rest to tie their shoelace which has come undone. After this, they run at constant speed to the finish line.

Complete the graph drawn in part (c) to show this motion.

Some children launch a toy water rocket into the air. Figure 1 shows how the displacement of the rocket changes over time.

Figure 1

Compare the rocket’s average speed as it travels upwards to its average speed as it travels back down.

Explain how the velocity of the rocket could be found at any given time from the distance-time graph in Figure 1

After 3 seconds, the water from the toy water rocket runs out.

In a scenario where there is no air resistance, explain the motion of the water rocket between 3 seconds to when it touches the ground, stating any relevant forces.

The graph shown in Figure 1 is a velocity time graph for a lift travelling between two different floors in a tall building.

Figure 1

Calculate the acceleration of the lift during the first 2 seconds. Show your working clearly and give your answer with appropriate units.

Explain the motion of the lift between 4-6 seconds by referring to Figure 1. State any important values.

The lift is now called to travel between two floors that are much further apart, with no stops in between.

Assuming that the lift has the same acceleration as before, explain how the graph in Figure 1 would change to reflect this.

Figure 1 shows a distance-time graph for a train.

State whether the train is travelling faster from A to B or from B to C.

Explain your answer.

Calculate the speed of the train from A to B.

Give your answer to 2 significant figures.

Higher Only

The velocity-time graph of another train is shown in Figure 2.

Using Figure 2, calculate the distance travelled in the first 6 hours.

Give your answer to 2 significant figures.   

Higher Only

Explain why the total displacement after 11 hours is less than your answer to part (c).

A train travels at a constant speed of 45.0 m/s.

Calculate the distance it travels in 1.50 minutes.

Give your answer to 3 significant figures.

Calculate how long it takes (in minutes) for the same train travelling at the same speed to travel 10.0 km.

Give your answer to 3 significant figures.

Higher Only

A toy train is made based on the train in parts (a) and (b). The toy train is shown in Figure 1.

A toy sign is placed at the side of the track.

The toy train is powered by a battery and moves along a circular track.

Compare the speed of the train and the velocity of the train.

Higher Only

The speed-time graph of the model train is shown in Figure 2.

The points at which the train passes the sign are indicated on the graph.

Calculate the circumference of the circular track.

Give your answer to 2 significant figures.

A commercial jet needs to reach a speed of 60 m/s before it can take off. It takes the jet 30 seconds to reach this speed.

Calculate the acceleration of the jet.

A larger jet needs to reach the same speed of 60 m/s to take off.

Explain how the motion of this jet will compare to that in part (a)

Higher Only

Figure 1 shows a diagram of the jet.

Figure 1

After take-off, the jet eventually reaches a constant velocity.

Draw arrows on Figure 1 to show the forces on the plane at constant velocity. Label your diagram.

A physics teacher jokes to her students that even objects with constant speed can be accelerating. 

Explain how this can happen.

Higher Only

A single ion is accelerating. The speed-time graph of the ion is shown in Figure 1.

Calculate the maximum acceleration of the ion.

Give your answer to 2 significant figures.

Calculate the average acceleration from = 0 s to = 0.9 s in Figure 1.

Give your answer to 2 significant figures.

Later, the ion is accelerated by an electric field at a constant rate of 50 m/s² over a distance of 2.0 × 10^-6 m.

The ion has a mass of 4.5 × 10^-26 kg. 

Calculate the work done on the ion by the electric field.

Give your answer to 2 significant figures.