A physics student obseved a train of 100 m long crossing a bridge of length 245 m . If the train is moving with a velocity of ` 54 km h^(-1)` , he determines the time taken by it to cross the bridge. Find his answer.

Explanation

Velocity of the train,
` v = 54 km h^(-1) = 54 xx 5/18 m s ^(-1) = 15 m s^(-1)`
In order to cross the bridge the train has to cover a distance equal to the sum of length of the bridge and the length of the train .
S = 100 m + 245 m = 345 m
Time taken to cross the bridge = t
` = (345)/15 = 23 s `