question_answer

                A boy of mass 20 kg is standing on a 80 kg free to move long cart. There is negligible friction between cart and ground. Initially, the boy is standing 25 m from a wall. If he walks 10 m on the cart toward the wall, then the final distance of the boy from the wall will be:     [JEE Main Online Paper ( Held On 23  April 2013 )

A)                   15 m                   

B)                                          12.5 m

C)                                          15.5 m                                

D)                                          17 m