A juggler is throwing balls up in the air and catching them. An observer in the crowd makes the statement that the potential and kinetic energy of the ball is the same when the ball is halfway down from its highest point. In one paragraph, using your own words, explain using the relationship of mechanical energy, potential energy, and kinetic energy why the observer is correct.

If a refrigerator is a heat pump that follows the first law of thermodynamics, how much heat was removed from food inside of the refrigerator if it released 380j of energy to the room?

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.

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?