question_answer

A train of 150 m length is going towards north direction at a speed of \[10\text{ }m{{s}^{-1}}\]. A parrot flies at a speed of \[5\text{ }m{{s}^{-1}}\] towards south direction parallel to the railway track. The time taken by the parrot to cross the train is equal to

A) 12s                  

B) 8s  

C) 15s                  

D) 16s

Correct Answer: D

Solution :

So by figure the velocity of parrot  w.r.t. train is S\[=5-(-10)\text{ }15m/sec\] so time taken to cross the train is =\[\frac{\text{length of train}}{\text{relative velocity}}=\frac{150}{15}=10\text{ sec}\]