Question

a train running at a speed of 45 km per hour is 400 m long how will long will it take to pass a vendor standing on the station platform

Answer 1

T=d/s
S= 45*1000=45000m
D=400
=45000/400

Answer 2

To pass a vendor standing on the platform the train must travel 400m.

45km=45000m/3600 sec=12.5m/sec

the train travels 12.5 m in 1 sec

∴, the train travels 400m in =1/12.5×400= 32 sec.