Answer: k/2.
- A k/2
- B 2k
- C k
- D k²
Correct answer: A. k/2
Explanation: Series: 1/keff = 1/k + 1/k = 2/k → keff = k/2. Series connection makes the effective spring softer.
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.