A 1 300 kg car traveling initially with a speed of 25.0 m/s in an easterly direction crashes into the back of a 9 600 kg truck moving in the same direction at 20.0 m/s. The velocity of the car right after the collision is 18.0 m/s to the east.
(a) What is the velocity of the truck right after the collision?
(b) What is the change in mechanical energy of the car-truck system in the collision? (Use input values with an adequate number of significant figures to calculate this answer.) J
(c) Account for this change in mechanical energy.