Serway & Jewett — Linear Momentum and Collisions: Problem 12

A 1 200-kg car traveling initially at \(v_{Ci} = 25.0\text{ m/s}\) in an easterly direction crashes into the back of a 9 000-kg truck moving in the same direction at \(v_{Ti} = 20.0\text{ m/s}\) (Fig. P9.12). The velocity of the car immediately after the collision is \(v_{Cf} = 18.0\text{ m/s}\) to the east. (a) What is the velocity of the truck immediately after the collision? (b) What is the change in mechanical energy of the car–truck system in the collision? (c) Account for this change in mechanical energy.