AQA AS Physics

Topic Questions

4.3 Equations of Motion

1a2 marks

A car, initially at rest, begins to move with an acceleration of 1.5 m s–2. 

Calculate the speed of the motor car after 20 s.

1b2 marks

Calculate the distance travelled by the motor car in the first 10 s of the motion.

1c1 mark

Calculate the distance travelled by the motor car in the first 20 s of the motion.

1d4 marks

Figure 1 shows the graph of acceleration against time together with two incomplete sets of axes.

Figure 1

4-3-s-q--q1d-medium-aqa-a-level-physics

Sketch on these axes the corresponding graphs of speed and distance travelled for the first 20 seconds of the car’s motion. 

You should include labels for the axes and any known numerical values.

Did this page help you?

2a4 marks

A digital camera was used to obtain a sequence of images of a tennis ball being struck by a tennis racket. The camera was set to take an image every 6.0 ms. The successive positions of the racket and ball are shown in Figure 1 below.

Figure 1

4-3-s-q--q2a-medium-aqa-a-level-physics

 

The ball has a horizontal velocity of zero at and reaches a constant horizontal velocity at as it leaves the racket. The ball travels a horizontal distance of 96 cm between and G. 

Calculate the horizontal acceleration of the ball between and D.

2b3 marks

At D, the ball was projected horizontally from a height of 3.4 m above level ground. 

Show that the ball would fall to the ground in about 0.8 s. 

Assume that only gravity acts on the ball as it falls.

2c2 marks

Calculate the horizontal distance that the ball will travel after it leaves the racket before hitting the ground. 

Assume that only gravity acts on the ball as it falls.

2d2 marks

Explain why, in practice, the ball will not travel this far before hitting the ground.

Did this page help you?

3a2 marks

Figure 1 shows the variation of velocity v with time t for a Formula 1 car during a test drive along a straight, horizontal track. 

Figure 1

4-3-s-q--q3a-medium-aqa-a-level-physics

State and explain which section of the graph shows that the car’s acceleration was uniform.

3b3 marks

Determine the distance travelled by the car during the first 5.0 s.

3c2 marks

Show that the instantaneous acceleration is about 16 m s−2 when t is 5.0 s.

3d6 marks

Figure 2 shows the aerofoil that is fitted to a Formula 1 car to increase its speed around corners. 

Figure 2

4-3-s-q--q3d-medium-aqa-a-level-physics

However, the aerofoil exerts an unwanted drag force on the car when it is travelling in a straight line so a Drag Reduction System (DRS) is fitted. This system enables the driver to change the angle of the aerofoil to reduce the drag. 

The graph in Figure 1 is for a test drive along a straight, horizontal track. Under the conditions for this test drive, the DRS was not in use and the engine produced a constant driving force. 

Explain why the velocity varies in the way shown in the graph. 

Go on to explain how the graph will be different when the DRS is in use and the driving force is the same. 

The quality of written communication will be assessed in your answer.

Did this page help you?

4a1 mark

Figure 1 shows a golfer hitting a ball from the top of a cliff. 

Figure 1

4-3-s-q--q4a-medium-aqa-a-level-physics

The ball follows the path shown. The ball is hit with an initial velocity of 46 m s−1 at an angle of 34° above the horizontal, as shown. Assume that there is no air resistance. 

Calculate the initial vertical component of velocity of the ball.

4b2 marks

At point Y the ball is level with its initial position. 

Show that the time taken to reach Y is about 5 s.

4c3 marks

The total time of flight of the ball is 10.0 s. 

Show on Figure 2 how v, the vertical component of the velocity, changes throughout the whole 10.0 s. 

Figure 2

4-3-s-q--q5c-medium-aqa-a-level-physics

4d3 marks

Calculate the height h of the cliff.       

4e2 marks

In practice, the air resistance affects the path of the ball. 

Draw on Figure 1the path the ball takes when air resistance is taken into account.

Did this page help you?

5a6 marks

The graph shows how the vertical speed of a parachutist changes with time during the first 20 s of his jump. To avoid air turbulence caused by the aircraft, he waits a short time after jumping before pulling the cord to release his parachute. 

Figure 1

4-3-s-q--q5a-medium-aqa-a-level-physics

Regions A, B and C of the graph show the speed before the parachute has opened. 

With reference to the forces acting on the parachutist, explain why the graph has this shape in the region marked. 

The quality of written communication will be assessed in your answer.

5b2 marks

Calculate the maximum deceleration of the parachutist in the region of the graph marked D, which shows how the speed changes just after the parachute has opened. Show your method clearly.

5c4 marks

Use the graph to find the total vertical distance fallen by the parachutist in the first 10 s of the jump. Show your method clearly.

5d2 marks

During his descent, the parachutist drifts sideways in the wind and hits the ground with a vertical speed of 5.0 m s–1 and a horizontal speed of 2.0 m s–1. 

Calculate the resultant speed with which he hits the ground and the angle his resultant velocity makes with the vertical.

Did this page help you?