Question

train 200m long crosses a bridge.300m long It enters the bridge with a speed of 30 m / s.and leaves it with a speed of 50 m / s, what is the time taken to cross the bridge? (A) 2.5 s (B) 7.5s (D) 15.0 (C) 12.5s

Answer 1

ans c .. here we should consider const acceleration to find average speed..