Question

practice it!
select the picture(s) that accurately illustrate kinetic energy.
top of hill
going into a loop
stationary at the entrance
almost to the bottom of the hill
going down the hill

Explanation:

Kinetic energy is the energy of motion. Objects that are moving have kinetic energy. In the context of a roller - coaster:

• When the roller - coaster is "going into a loop", it is in motion, so it has kinetic energy.
• When it is "almost to the bottom of the hill", it is moving (due to the conversion of potential energy to kinetic energy as it descends), so it has kinetic energy.
• When it is "going down the hill", it is in motion (accelerating due to gravity in the direction of the slope), so it has kinetic energy.
• When it is at the "top of the hill", its velocity is relatively low (assuming it is just about to start descending, more potential energy than kinetic).
• When it is "stationary at the entrance", its velocity \(v = 0\). Using the formula for kinetic energy \(K.E.=\frac{1}{2}mv^{2}\), if \(v = 0\), then \(K.E.=0\).

Answer:

going into a loop, almost to the bottom of the hill, going down the hill.