Question

practice it!
which of the following accurately describes what is happening at point a, as seen in the image given
kinetic energy is changing into potential.
potential energy is being stored.
kinetic energy is being stored.
potential energy is changing to kinetic energy.

Explanation:

At the highest point (point A) of the roller - coaster, the roller - coaster has maximum potential energy (due to its height \(h\), \(PE = mgh\)) and minimum kinetic energy (as its speed \(v\) is minimum, \(KE=\frac{1}{2}mv^{2}\)). As it moves down from point A, its height \(h\) decreases (so potential energy decreases) and its speed \(v\) increases (so kinetic energy increases). So, potential energy is changing to kinetic energy.

Answer:

Potential energy is changing to kinetic energy.