A simple pendulum has time period 2 s. Its point of suspension is moved upward according to y = (6t - 3.75t²) m, where t is in seconds. The new time period is:
Options

Question

A simple pendulum has time period 2 s. Its point of suspension is moved upward according to y = (6t − 3.75t²) m, where t is in seconds. The new time period is:

G1 Physics · Accepted Answer

The suspension acceleration is ÿ=−7.5 m s⁻², i.e. downward. Taking g=10 m s⁻², effective gravity is g′=10−7.5=2.5 m s⁻². Since original T=2 s, T′=T√(g/g′)=2√(10/2.5)=4 s. Correct answer: C.