Question

the image shows a pendulum that is released from rest at point a. shari tells her friend that no energy transformation occurs as the pendulum swings between point b and point d. what is the best response that sharis friend could make? she could agree with shari because the pendulum is at the same height and would have the same gravitational potential energy at both positions. she could agree with shari because the pendulum has the same amount of mechanical energy throughout its swing. she could disagree with shari because the pendulum converts kinetic energy into gravitational potential energy, then back into kinetic energy. she could disagree with shari because the pendulum converts gravitational potential energy into kinetic energy, then back into gravitational potential energy.

Explanation:

As a pendulum swings, at the highest - points (like A, B, D, E) it has maximum gravitational potential energy and minimum kinetic energy. At the lowest - point (C) it has maximum kinetic energy and minimum gravitational potential energy. Energy transformation occurs between gravitational potential and kinetic energy as it swings, so Shari is wrong.

Answer:

D. She could disagree with Shari because the pendulum converts gravitational potential energy into kinetic energy, then back into gravitational potential energy.