Two bears sit on a see-saw. The see-saw is 3.5 m in total length with the fulcrum at the center. A 40 kg baby bear sits at the very end of one side. Where should the 120 kg father bear sit relative to the center to keep the see-saw balanced?

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.