Question

A 150 m long train is moving to north at a speed of 10 m/s. A parrot flying towards south with a speed of 5 m/s crosses the train. The time taken by the parrot the cross to train would be:

• A. 30 s
• B. 15 s
• C. 8 s
• D. 10 s

Answer 1

Answer: (D)

10 s

Answer 2

Relative velocity of parrot with respect to train

=$5 - ( - 10) = 5 + 10 = 15m/\sec$

Time taken by the parrot

$= \frac{d}{v_{\text{rel.}}} = \frac{150}{15} = 10sec.$