(a) what force does a trampoline have to apply to jennifer, a 45.0-kg gymnast, to accelerate her straight upward at 7.50 m/s2? (b) does your answer to part (a) depend on whether jennifer is in the process of landing on the trampoline (downward velocity) or being propelled off the trampoline (upward velocity)?

Complete these sentences. if a roller coaster train has a potential energy of 1,500 j and a kinetic energy of 500 j as it starts to travel downhill, its total energy isj. once the roller coaster train gets closer to the bottom of the hill, its kinetic energy increases to 1,100 j, and its potential energy decreases to j. when the train reaches the bottom of the track and is traveling along the ground, its kinetic energy isj.