Question

A train crosses a pole in 12 seconds. If the length of the train is 120 metres, find its speed in metres / sec and in km/ hour.

Answer 1

Train crosses a pole in 12 sec. it means train crosses its own length. · i.e. train covers 160 m in 12 sec. · So the speed of train = 160/12 = 40/ 3 ...

Answer 2

Distance travelled by train = The length of the train.

So speed in m/s = length of train/time taken to cross the pole

v= 120/12

= 10m/s

To convert it to km/h multiply 3600 in numerator and multiply 1000 in denominator.

v(in km/h) = 10×3600÷1000 = 36km/h.