1.1. Extended tier only

Fig. 2.1 shows a train.

The total mass of the train and its passengers is 750 000 kg. The train is travelling at a speed of 84 m/s. The driver applies the brakes and the train takes 80 s to slow down to a speed of 42 m/s.

Calculate the impulse applied to the train as it slows down.

impulse = .........................................................

1.2. Extended tier only

Calculate the average resultant force applied to the train as it slows down.

force = .........................................................

1.3. Suggest how the shape of a modern electric train helps it to travel at high speeds.

1.4. The train took 80 s to reduce its speed from 84 m/s to 42 m/s. Explain why, with the same braking force, the train takes more than 80 s to reduce its speed from 42 m/s to zero.

1.5. On a wet day, the train travels a greater distance before it stops along the same track. The train has the same speed of 84 m / s before the brakes are applied.

  Suggest a reason for this.