A 1120-kg car with an initial velocity of 21.0 m/s eastward crashes into the back of a 3180 kg cargo van, which has an initial velocity of 14.3 m/s eastward. Immediately after the collision occurs, the velocity of the car is 12.5 m/s eastward. The collision occurs along a straight level road. How much kinetic energy is lost from the car-van system during this process?