Question

A railway train 100 metre long is runing at speed of 30 km/h in what time it pass a bridge 80 metre long

Answer 1

To cross the bridge completely, the train has to cover a distance equal to the sum of length of train and the bridge.

Total length = 100 + 80 = 180 m

speed = 30 km/h

convert it into m/s:

30 km/h = 30 × 5/18 = 25/3 m/s

Time = distance÷speed = 180 ÷ 25/3 = 180×3/25 = 21.6 seconds

Thus, it will take 21.6s to cross the bridge