When the pendulum shown below swings from point A to point B, what happens to its total mechanical energy (ignoring friction)?

Answer 1

When the pendulum swings from point A to point B while ignoring friction and air resistance, its total mechanical energy remains constant. The total mechanical energy of the pendulum is the sum of its potential energy (PE) and kinetic energy (KE).

At point A (the highest point), the pendulum has maximum potential energy and minimum kinetic energy. As it swings down towards point B, potential energy converts into kinetic energy, increasing the pendulum's speed. At point B (typically the lowest point), the pendulum has maximum kinetic energy and minimum potential energy.

Throughout this motion, the total mechanical energy, given by the equation \( E = PE + KE \), stays constant. This is a result of the conservation of energy principle.

Answer 2

B is swinging to the left and A is staying in the middle not moving

A. Total mechanical energy goes down.

B. Total mechanical energy goes up.

C. Total mechanical energy is not conserved.

D. Total mechanical energy stays the same.

Answer 3

Given the scenario where point A is stationary in the middle and point B is swinging to the left, the correct answer regarding the total mechanical energy of the pendulum (assuming no friction or air resistance) is:

D. Total mechanical energy stays the same.

This indicates that despite the motion of the pendulum from point A to point B, the total mechanical energy remains constant, owing to the conservation of mechanical energy in the absence of non-conservative forces.