Question

multiple-choice question
why does the total energy stay the same as the pendulum swings?
the potential energy is converted into kinetic energy and back to potential energy as it swings down and up.
because the pendulum never speeds up or slows down at any point, so its kinetic energy never changes.
because the height of the pendulum never goes up or down, so its potential energy never changes.

Explanation:

A pendulum’s total energy remains constant because gravitational potential energy (related to height) converts to kinetic energy (related to speed) when swinging down, and reverses when swinging up—no net energy loss in an ideal system. The other options are incorrect: the pendulum does speed up/slow down (changing kinetic energy) and change height (changing potential energy).

Answer:

The potential energy is converted into kinetic energy and back to potential energy as it swings down and up.