For a simple pendulum undergoing small oscillations
PHYSICS · Single correct · AP · Physics 1: Algebra-based · Oscillations · Oscillations
Problem
For a simple pendulum undergoing small oscillations, which statement best explains why its motion can be modeled as simple harmonic motion when described in either angular or linear variables?
(a) The tension in the string acts as a constant-magnitude restoring force that always points toward the equilibrium position, producing simple harmonic motion.
(b) The restoring torque is proportional to the angular displacement, so the tangential restoring force is proportional to the corresponding linear displacement.
(c) The restoring torque is the same for all angles, giving the bob a uniform angular acceleration and therefore simple harmonic motion.
(d) For small angles, the tangential component of gravity varies with the square of the angular displacement, which yields the linear acceleration needed for simple harmonic motion.