At which position does a pendulum experience "no work by gravity"?

A pendulum experiences "no work by gravity" when it is at the lowest point of the swing. At this position, the pendulum's potential energy is at its minimum and kinetic energy is at its maximum. Gravity acts as a conservative force, and the work done by gravity relates to the change in potential energy.

At the lowest point, the height of the pendulum mass is zero relative to the lowest position, which means there is no vertical displacement occurring at that precise moment; thus, the gravitational force does not do any work. The energy is fully kinetic, allowing the pendulum to be at that point of maximum speed.

Consequently, since there is no change in height while the pendulum is at this lowest point, no work is being performed by gravity at that exact position. In contrast, at the highest points and various other positions during its swing, changes in height occur, resulting in work being done by gravity as it either pulls the pendulum down or allows it to ascend.