Question

energy
law of conservation of energy
(achieving)
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.
kinetic energy is being stored.
potential energy is being stored.
potential energy is changing to kinetic energy.

Explanation:

At the highest point (point A) of a roller - coaster, the roller - coaster has maximum height. According to the formula for gravitational potential energy \(U = mgh\) (where \(m\) is mass, \(g\) is acceleration due to gravity, and \(h\) is height), when height \(h\) is maximum, potential energy is maximum. Kinetic energy \(K=\frac{1}{2}mv^{2}\). At the top of the loop (point A), the velocity \(v\) is relatively small (instantaneously, the roller - coaster is at rest in the vertical direction at the very top of the loop for an idealized case), so kinetic energy is small. So, potential energy is being stored at point A.

Answer:

Potential energy is being stored.