A train is moving at a speed of 63m/s. It takes 8 seconds to cross a jeep that is travelling in the opposite direction at a speed of 70m/s. What is the length of the train?
The distance to be covered is equal to the length of the train. This distance has to be covered at a net relative speed equal to the sums of the speeds of the jeep and the train, so v = 63 + 70 = 133. The length of the train will be time × speed = $8 × 133$ = 1064meters.