Which statement accurately describes simple harmonic motion?

• A. It is periodic motion but not oscillatory
• B. It involves motion under constant acceleration
• C. It is characterized by a restoring force directly proportional to displacement
• D. It has a speed that remains constant throughout the motion

Answer: (C)

In simple harmonic motion (SHM), one of the defining characteristics is the presence of a restoring force that is directly proportional to displacement from the equilibrium position. This means that when an object is displaced, it experiences a force that drives it back toward the equilibrium point. Mathematically, this is often expressed as ( F = -kx ), where ( F ) is the restoring force, ( k ) is a positive constant (the stiffness of the system), and ( x ) is the displacement from equilibrium. This relationship leads to the oscillatory nature of SHM, allowing the system to exhibit periodic motion.

In contrast, while periodic motion does occur in SHM, the statement regarding constant acceleration does not typically apply, as the acceleration varies depending on the position of the object. The motion also does not maintain a constant speed; instead, the speed changes as the object moves through its cycle, being greatest at the equilibrium position and zero at the maximum displacement points. Thus, the correct understanding of simple harmonic motion hinges on the proportional relationship between the restoring force and displacement.