Question

A train travelling at a speed of $54$ km/hr crosses a lamp post in $20$ second. What is the length of the train?

Answer 1

Time taken by train to cross lamp post$=20s$

Speed of train$=54$ km/hr$=54\times \frac{1000}{3600}$ m/s

Speed$=15$ m/s

length of train$=$speed$\times$time

$=\frac{15m}{s}\times 20s$

$=300m$

$\therefore$ Length of train$=300$m.