Physics (AS & A Level) · May / June 2026 · Paper 12 · Question 7

The diagram shows an arrangement to stop trains that are travelling too fast. Trains coming from the left travel at a speed of 50 m s⁻¹. At marker 1, the driver must apply the brakes so that the train decelerates uniformly in order to pass marker 2 at no more than 10 m s⁻¹. The train carries a detector that notes the times when the train passes each marker and will apply an emergency brake if the time between passing marker 1 and marker 2 is less than 20 s. How far from marker 2 should marker 1 be placed?

1. A200 m
2. B400 m
3. C500 m
4. D600 m

As printed in the paper