Question

a train 150m long is running at 72km/h it crosses a bridge in 13 second find the length of the bridge

Answer 1

Hey There Here's your answer...

Length of bridge= total distance-lenght of train.--(1)

Now total distance= speed × time = 72km/hr× 0.0036hr ( since 13 sec = 0.0036 hr )
= 0.27km = 270m

Now from 1 we get

length of bridge= 270m- 150m = 120m

Answer 2

Speed of train in m/s

= 72×1000/3600

= 20m/s

According to question

Length of bridge = speed × time - 150

= 20 ×13 -150

= 110m

Length of bridge 110m