Answer: π/3 s.
- A π/3 s
- B 2π/6 s
- C 6π s
- D π/6 s
Correct answer: A. π/3 s
Explanation: Comparing with a = -ω²x: ω² = 36 → ω = 6 rad/s. T = 2π/ω = 2π/6 = π/3 s.
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.