Two parallel rail tracks run north-south. Train A moves north with the speed of `15m/s`and train B moves south with the speed of `25 m/s`. What is the velocity of B with respect to A?

Two parallel rail tracks run north-south. Train A moves north with the speed of 15m/s and train B moves south with the speed of 25 m/s . What is the velocity of ground with respect to B?

Two parallel rail tracks run north-south. Train A moves north with the speed of 15m/s and train B moves south with the speed of 25 m/s . What is the velocity of a monkey running on the roof of the train A against its motion (with a velocity of 5 m/s with respect to the training A)as observed by a man standing on the ground?

A car travels with a speed of 25 m//s for 2 minutes and then with 20 m//s for 1 minute.What is its average speed?