Question

A train of length 300 meters is travelling with a speed of 54 km/hr .It takes 40 seconds to cross a bridge , then the length of the bridge will be.

Answer 1

speed=54km as 15m/sec

distance=300mts

time=d/s=300/15=20sec

total time=40+20=60sec

distance=15of 60=900mts

Answer 2

Answer:

300 m

Explanation:

Time taken by the train to cover the distance of the train.

Time = Distance / Speed

$\text{Time}=\frac{300}{\frac{54}{3.6}}=20\ seconds$

Time taken to cross the bridge means time taken by the train by the train from the entry of the head of the train to the point in time where the end of the trian leaves the end of the train = 40 seconds.

So, time taken by the train from the head entering to the head exiting is 40-20 = 20 seconds.

Distance = Speed × Time

$\text{Distance}=\frac{54}{3.6}\times 20=300\ m$

Hence, the distance of the bridge is 300 m