A 1200 kg car travelling initially with a speed of 25.0 m/s in an easterly direction crashes into the rear end of an 8800 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) How much mechanical energy is lost in the collision? (Utilize input values by an adequate number of important figures to calculate this answer.)