A train is moving on a straight track with a speed of
PHYSICS · Subjective · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A train is moving on a straight track with a speed of 60km h−1. The driver first applies a light braking giving the train a uniform retardation of 0.5m s−2 that lasts for 20s, after which a stronger braking is applied producing a uniform retardation of 1.5m s−2 until the train comes to rest.
(i) Find the speed of the train at the instant the stronger braking begins.
(ii) Calculate the additional time required after this instant for the train to come to rest.
(iii) Determine the total distance travelled by the train from the moment the light braking is first applied until it stops completely.