Answer: 2.
- A 2
- B √2
- C 1/2
- D 1/√2
Correct answer: A. 2
Explanation: Original k<sub>eff</sub> = k + 3k = 4k. After cutting (say k<sub>1</sub> remains): k<sub>eff</sub> = k. T ∝ 1/√k<sub>eff</sub>. T<sub>new</sub>/T<sub>old</sub> = √(4k/k) = 2.
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.