Uniformly accelerated motion and motion graphsEdexcel A-Level Physics: Subtopic test

1. 1
   A train leaves a station and accelerates uniformly from rest. After 40 s it has reached a speed of 20 m s⁻¹. It then continues at this constant speed.

   (a)

   What is the acceleration of the train during the first 40 s?

   [1 mark]

   • A0.25 m s⁻²
   • B2.0 m s⁻²
   • C0.50 m s⁻²
   • D800 m s⁻²

   (b)

   What distance does the train travel in the first 40 s?

   [1 mark]

   • A400 m
   • B800 m
   • C200 m
   • D10 m

   (c)

   The train then travels at 20 m s⁻¹ for a further 90 s. Calculate the total distance travelled in the 130 s.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A student investigates free fall by dropping a small steel ball from rest. A timer starts when the ball is released and stops when the ball strikes a trapdoor switch 1.50 m below. Air resistance may be ignored.

   (a)

   Which equation of motion allows g to be found from the measured fall distance s and fall time t alone?

   [1 mark]

   • Av² = u² + 2as
   • Bs = ut + ½at², with u = 0 and a = g
   • Cv = u + at
   • Ds = ½(u + v)t

   (b)

   Taking g = 9.81 m s⁻², how long does the ball take to fall 1.50 m?

   [1 mark]

   • A0.31 s
   • B0.39 s
   • C0.15 s
   • D0.55 s

   (c)

   In one trial the ball takes 0.560 s to fall the 1.50 m. Calculate the value of g given by this trial.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A lift in a tall building starts from rest at the ground floor. It accelerates uniformly at 1.2 m s⁻² for 3.0 s, moves at constant velocity for 8.0 s, then decelerates uniformly to rest in 2.0 s.

   (a)

   Calculate the maximum speed reached by the lift and the magnitude of its deceleration in the final stage.

   [3 marks]

   (b)

   Calculate the total height risen by the lift, by considering the area under its velocity–time graph.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A ball is released from rest above a hard floor, bounces once and is caught at the top of its first rebound. A motion sensor records its velocity every 0.01 s. Upwards is taken as positive.

   (a)

   Describe and explain the shape of the velocity–time graph from the moment of release until the ball is caught.

   [6 marks]

   (b)

   The ball is released from rest 1.80 m above the floor and rebounds with 80% of its impact speed. Calculate its impact speed and the height reached after the bounce. Explain how the sensor data could be used to check this height, and evaluate whether it is reasonable to take the acceleration as exactly 9.81 m s⁻² throughout.

   [6 marks]

   Total for question 4: 12 marks

End of questions