select the correct locations on the image. mechanical energy is the sum of an objects potential energy and…

select the correct locations on the image. mechanical energy is the sum of an objects potential energy and kinetic energy. consider the positions of this swinging pocket watch. at which positions will the potential energy be the highest? assume the pendulum can swing forever (ignore friction).
Answer
Answer:
The positions at the two extreme - ends of the swing.
Explanation:
Step1: Recall energy conservation
Mechanical energy $E = PE+KE$ is conserved.
Step2: Analyze kinetic and potential energy
At the extreme - ends, the velocity $v = 0$, so $KE=\frac{1}{2}mv^{2}=0$. Since $E$ is constant, when $KE = 0$, $PE$ is maximum.