Question

A 120 m long train is moving towards west with a speed of 10 m/s. A bird flying towards east with a speed of 5 m/s crosses the train. The time taken by the bird to cross the train will be

• A. 16 sec
• B. 12 sec
• C. 10 sec
• D. 8 sec

Answer 1

Answer: (D)

8 sec

Answer 2

Relative velocity$= 10 + 5 = 15m/s$

Time taken by the bird to cross the train$= \frac{120}{15} = 8\sec$