Question

The image shows a pendulum that is released from rest at point A. Which energy transformation is correct? From A to C, kinetic energy is transformed into gravitational potential energy. From C to D, kinetic energy is transformed into gravitational potential energy. From C to E, gravitational potential energy is transformed into kinetic energy. From D to E, gravitational potential energy is transformed into kinetic energy.

Answer 1

Answer:

Partially: From C to D, kinetic energy is transformed into gravitational potential energy and From D to E, gravitational potential energy is transformed into kinetic energy

Explanation:

What happens in this pendulum is that at point A, there's only gravitational potential energy (no velocity=no kinetic energy)

At point C, it has maximum speed since all of the potential energy is transformed into kinetic energy (no potential gravitational  energy at this point)

At point E, it is the same as at point A. (no kinetic energy)

At the intermediate points (B and D) there are both kinetic and potential energy. At point B the kinetic energy is increasing and at point D it is decreasing.

Now let's see each case:

- From A to C, kinetic energy is transformed into gravitational potential energy: It is actually the opposite, so no.

- From C to D, kinetic energy is transformed into gravitational potential energy: Yes, but not all of it is transformed since it still has kinetic energy that allows it to get til point E.

- From C to E, gravitational potential energy is transformed into kinetic energy: No, it is the opposite.

- From D to E, gravitational potential energy is transformed into kinetic energy: Yes, but not all of it, since at point D it also has kinetic energy.

Answer 2

Answer:

From C to D, kinetic energy is transformed into gravitational potential energy.

i think