Question

a 250 m long train is moving at a constant speed of 72km/h. how much time will take to cross bridge 150 m long

Answer 1

Answer:

It will take 20 seconds to cross the bridge.

Step-by-step explanation:

Speed of the train = 72 km per hour

∵ 1 km = 1000 meter

∴ 72 km = 72 × 1000 = 72,000 meter

1 hour = 3600 seconds

Speed of the train =  = 20 meter/sec.

distance covered by train = length of the train + length of the bridge.

distance covered = 250 + 150

                            = 400 meter

Speed = distance/time

Let the time taken by the train  t sec.

20 = 400/t

20t = 400

t = 400/20

t = 20