Answer: 2π√(I/k T ).
- A 2π√(I/k<sub>T</sub>)
- B 2π√(k<sub>T</sub>/I)
- C 2π√(I/M)
- D 2π√(I k<sub>T</sub>)
Correct answer: A. 2π√(I/k<sub>T</sub>)
Explanation: For torsional SHM: τ = -k<sub>T</sub> θ, giving Iα = -k<sub>T</sub> θ. ω² = k<sub>T</sub>/I. T = 2π√(I/k<sub>T</sub>).
In SHM, displacement and velocity are 90° out of phase (v is maximum when x=0, and zero when x is extreme), while acceleration is always exactly opposite in sign to displacement, consistent with a = −ω²x.
Concept context
Simple harmonic motion, spring-mass, pendulum, energy in SHM, and resonance.