Question

A simple pendulum hanging freely and at rest is vertical because in that position ___________

(a) Kinetic energy is zero

(b) Potential energy is zero

(c) Kinetic energy is minimum

(d) Potential energy is minimum

I had been asked this question at a job interview.

I'd like to ask this question from Moment of Inertia topic in portion System of Particles and Rotational Motion of Engineering Physics I

Answer 1

Correct option is (d) Potential energy is minimum

Easiest explanation: In the position of equilibrium, the potential energy of the simple pendulum is minimum. Therefore a simple pendulum hanging freely and at rest is vertical because in that position potential energy is minimum.