where 
is the length of the pendulum, and 
is the magnitude of the acceleration due to gravity. [P5.1]
is: a periodic swinging system, driven by a gravitational restoring force. [P5.1]
has: in the simple (undamped) case, period where is the length of the pendulum, and is the magnitude of the acceleration due to gravity. [P5.1]
Copyright 1997, The Open University