Question

A 60 m long train moving on a straight level track passes a pole in 5 s, find the speed of the train and the time it will take to cross a 540 m long bridge.

• A. 13 m/s, 40 s
• B. 25 m/s, 30s
• C. 12 m/s, 50s
• D. 15 m/s, 65 s

Answer 1

The correct option is C

12 m/s, 50s

Speed of the train $=\frac{\text{Length of the train}}{\text{Time taken to cross the pole}}$
$=\frac{60}{5}\frac{m}{s}$
$=12\frac{m}{s}$

Now, distance to be covered to cross a $540m$ long bridge:
=Length of the train + Length of the bridge
$=60m+540m=600m$

Hence time taken $=\frac{distance}{speed}$
$=\frac{600}{12}s=50s$