Question

A train 100m long moving with a constant velocity of 60km/hr find the time it takes to cross the bridge 1 km long

Answer 1

Total distance = 1 km + 100m
= 1100 m
Speed of train = 60 km/ hr
= 16.6 m/s
Time taken = distance/speed 
= 1100/16.6
= 66.026 sec

Answer 2

Total distance required for the train to cross the bridge is,

d = (100 + 1000) m = 1100 m

The speed of the train is,

v = 60 km/h = 60 × 5 / 18 = (50/3) m/s

Hence the time taken to cross the bridge is,

t = 1100 / (50/3) = 66 s.