As a 1240-kg truck travels up a 15.4-m-high hill, the nonconservative forces of friction and the force generated by the engine do work on the truck. If the work done by friction is ?3.16 105 J and the work done by the engine is +6.39 105 J, determine the change in the truck's kinetic energy as it travels from the bottom of the hill to the top of the hill.