Two parallel rail tracks are in north-south direction. Train A moves towards north with a speed of 72 `kmh^(-1)` and train B moves towards south with a speed of 108 `kmh^(-1)` What is the (a) velocity of B with respect to A ?, (b) velocity of ground with respect to B ? and (c) velocity of a monkey running on the roof of the train A against its motion (with a velocity of 27 `kmh^(-1)` with respect to the train A) as observed by a man standing on the ground?

Explanation

(a) `-50 ms ^(-1),`
(b) Velocity of B w.r.t. ground `= 30 ms ^(-1),`
(c ) Velocity of monkey `= 12.5 ms ^(-1)`