Suppose you are to investigate an accident in which a 1300 kg car A struck a parked 1200 kg car B. All four of B's wheels were locked and skid marks indicate that B slid 2 m after impact. If you estimate the coefficient of kinetic friction between B's tires and the road to be 0.4 and the coefficient of restitution to be 0.4, what was the velocity of A just before impact. Assume only one impact occurred. The answer is 7.7 m/s, but im not sure how to get that.