Question

a train 400 m long is travelling at the speed of 72 km per hour. how long will it take to cross a lamp post ? ​

Answer 1

Answer:

Length of the train = Distance covered by it to cross the lamp post

Therefore, Distance = 400 m

Speed = 72 km per hour

= 72×5/18 metre per second

= 4 × 5 metre per second

= 20 metre per second

Now , The formula of time = Distance / Speed

= 400/20 seconds

= 20 seconds. ( Ans )

Answer 2

Answer:

10s

Step-by-step explanation:

a train 400 m long is travelling at the

speed of 72 km per hour

speed= 72*5/9=40 m/s

time= distance/speed=400/40=10s

time taken to cross a lamp post =10 sec