Question

A 160 m long train moving on a straight level track passes a pole in 10 s, find the speed of the train and the time it will take to cross an 840 m long bridge.

• A. 13 m/s, 40 s
• B. 25 m/s, 30 s
• C. 16 m/s, 62.5 s
• D. 16 m/s, 30 s

Answer 1

The correct option is C

16 m/s, 62.5 s

Speed of the train $=\frac{\text{Length of the train}}{\text{Time taken to cross the pole}}=\frac{160}{10}m/s=16m/s$

Now, distance to be covered to cross a 840 m long bridge
=Length of the train + Length of the bridge
= 160 m + 840 m = 1000 m

Hence, time taken $=\frac{distance}{speed}$
= $\frac{1000}{16}$ s = 62.5 s