PENDULUMS
You may see a question about pendulums on the SAT Physics Subject Test, so we’ll
cover them in this chapter. A simple pendulum consists of a weight of mass m
(called the bob) attached to a massless rod that swings, without friction, about the
vertical equilibrium position. The restoring force is provided by gravity and as the
figure below shows, the magnitude of the restoring force when the bob is at an
angle θ to the vertical is given by the equation
Frestoring = mg sin θ