Question

2 trains are running in opposite direction at 50 kmph and 58 kmph. The faster train crosses a man in the slower train in 5 seconds. Find the length of faster train.
1. 200 meter
2. 150 meter
3. 140 meter
4. 120 meter

Answer 1

Correct Answer - Option 2 : 150 meter

Given: crossing time = 5 seconds

Formula used :Time = Distance/ Speed = [Length of faster train + Length of man] / Relative Speed

Also, since two trains are running opposite to each other

Relative Speed (RS) = Speed of faster train + [Speed of man(= Speed of slower train)]

Calculation:

Accordingly,

RS = (50 + 58) kmph = 108 kmph

⇒ 108 × 5/18 m/s = 30 m/s

Time = [Length of faster train + Length of man] / Relative Speed

⇒ 5 = [Length of faster train + 0] / 30

⇒ Length of faster train = 5 sec. × 30 m/s = 150 meter

∴ The length of the faster train is 150 meter.