A 1,240-kg car traveling initially with a speed of 25.0 m/s in an easterly direction crashes into the rear end of a 8,200-kg truck moving in the same direction at 20.0 m/s (see figure below). The velocity of the car right after the collision is 18.0 m/s to the east. +25.0 m/s +20.0 m/s + 18.0 m/s Before After (a) What is the velocity of the truck right after the collision? (Round your answer to at least three decimal places.) m/s (east) (b) How much mechanical energy is lost in the collision? Account for this loss in energy