A 1083 kg van, stopped at a traffic light, is hit directly in the rear by a 745 kg car traveling with a velocity of +2.25 m/s.

A 1083 kg van, stopped at a traffic light, is hit directly in the rear by a 745 kg car traveling with a velocity of +2.25 m/s. Assume that the transmission of the van is in neutral, the brakes are not being applied, and the collision is elastic. What is the final velocity of the car