Answer: 2π√(m/(k)) (same as before).
- A 2π√(m/(k)) (same as before)
- B 2π√(m(g+a)/k) in many documented cases
- C 2π√(m(g-a)/k) according to conventional understanding
- D Depends on mass in routine practice
Correct answer: A. 2π√(m/(k)) (same as before)
Explanation: For a spring-mass system, T = 2π√(m/k). This does NOT depend on gravity, so acceleration of lift has no effect. (For a pendulum, effective g changes, but not for spring-mass).
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.