Question

A 25 m long train moving on a straight level track passes a pole in 5 s, find the time taken by the train to cross a 50 m long bridge(in s).

• A. 15

Answer 1

The correct option is A 15

Speed of the train $=\frac{\text{Length of the train}}{\text{Time taken to cross the pole}}=\frac{25}{5}\text{m/s}=5\text{m/s}$

Now, distance to be covered to cross a 50 m long bridge
$=$ Length of the train + Length of the bridge
$=$ 25 m + 50 m
$=$ 75 m

Hence, time taken $=\frac{\text{Distance}}{\text{Speed}}$
$=\frac{75}{5}$ s
$=15$ s