Question

A simple pendulum can be used as an altimeter on a plane. how will the period of the pendulum vary as the plane rises from the ground to its final cruising altitude?

Answer 1

The period will increase as the altitude increases.

Answer 2

As the plane rises, the distance between the pendulum and the center of the Earth increases which means that the force of gravity is decreased. With that, the swinging of the pendulum will be less restricted. The answer would be, the period of the pendulum will be greater.