Which statement explains how planets move in orbit as supported by Newton’s first law of motion? Planets can change the direction of their own orbital path.
Planets can change orbits due to their inertia.
Planets in motion will have a constant speed unless acted on by an outside force.
Planets with a greater mass will orbit more quickly than smaller planets.

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.