Question

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

Given,

Length of the train = $60m$

Time taken to cross the pole = $5s$

Length of the bridge = $540m$

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

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