Answer: 3.18 Hz.
- A 3.18 Hz
- B 6.37 Hz
- C 20 Hz
- D 1.59 Hz
Correct answer: A. 3.18 Hz
Explanation: f = (1/2π)√(k/m) = (1/2π)√(80/0.2) = (1/2π)√400 = 20/(2π) = 3.18 Hz.
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.