Question

a train moving with a speed of 72 km/hr crosses a man in 5 secs.it will cross a platform 60 metres long in​

Answer 1

In the case of crossing a man

Speed of train = 72 km/ hr = 20m/s

Time taken to cross a man ( or its own lenght) = 5s

Lenght of the train = 20 × 5 = 100m

In the case of crossing a platform

Total lenght crossed by train = ( lenght of train + lenght of platform) = 100 + 60

= 160m

Speed of train = 20m/s {given}

time taken to cross the platform = 160

20

= 80s

= 1min 20s