Question

The image shows a pendulum that is released from rest at point A.

An illustration of a pendulum at 5 different positions. The central position, the equilibrium position is labeled C. The two positions on the left are labeled A and B respectively. The two positions on the right are labeled D and E respectively. All positions are equally spaced.

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

Only the second statement is correct: From C to D, kinetic energy is transformed into gravitational potential energy.

Reason: C is the lowest point (maximum kinetic energy). As the bob moves upward toward D it slows down, so kinetic energy is converted into gravitational potential energy. The other statements have the direction of energy flow reversed.