How many moons does each planet have?

Most energy in an ecosystem comes originally from_

Which of the following are properties of mechanical waves? check all that apply ⭕️ particles of the medium move back and fourth, but do not move with the wave. ⭕️ the particles of the medium always move parallel to the wave motion. ⭕️ wave motion begins with a disturbance in the medium. ⭕️ waves transport energy from a source outward, away from the source.

Why is the energy that results from a roller coaster's position at the top of a hill referred to as potential energy?