Answer: At the extreme positions.
- A At the extreme positions
- B At the mean position
- C Everywhere equally
- D Midway between mean and extreme
Correct answer: A. At the extreme positions
Explanation: Acceleration a = -ω<sup>2</sup>x is proportional to displacement, so it is largest in magnitude where x is largest, i.e. at the extreme positions. It is zero at the mean position.
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.