A truck with a mass of 4285 kg is moving at 9.35 m/s. It crashes into the rear end of a larger truck with a mass of 5495 kg moving at 6.35 m/s in the same direction. What is the final velocity if the trucks lock together? How much does the kinetic energy decrease in the collision?Knowns Unknowns

ma = mb = vf = ?

vai = vbi = ΔKE = ?
(remember vaf = vbf = vf)

Solve for the Unknowns

a. Use conservation of momentum to find final velocity
b. First calculate KEf and Kei, then use these to determine ΔKE