Answer: T/6.
- A T/6
- B T/4
- C T/3
- D T/12
Correct answer: A. T/6
Explanation: x = a cos(ωt). x = a at t=0. x = a/2 when cos(ωt) = 1/2, so ωt = π/3, giving t = π/3ω = T/6.
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.