Question

A simple pendulum is attached to the roof of a lift. If the time period of oscillation, when the lift is stationary is T, then the frequency of oscillation when the lift falls freely, will be ___________

(a) Zero

(b) T

(c) 1/T

(d) ∞

The question was posed to me in examination.

This intriguing question originated from Oscillatory Motion in portion Oscillations of Engineering Physics I

Answer 1

The correct option is (a) Zero

The explanation: In a freely falling lift,

g=0

v=1/2π×√(g/l)=1/2π×√(0/l)=0.