[" Example "3.9" Two parallel rail tracks run "],[" north-south.Train A moves north with a "],[" speed of "54kmh^(-1)" ,and train "B" moves south "],[" with a speed of "90kmh^(-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 "],[" iwitb a velocity uf "18kmh^(-1)" with "],[" respeet to the train "A" ) as observed by "],[" a man standing on the ground? "]]