Animated Pendulum

To see an animated version of this see the mathematica demonstration on an animated pendulum.

This demonstration will enable you to visualise the partitioning of total energy between kinetic and potential, as well as dynamically changing the values of variables including graviaty, mass and length of the string.

To see the forces acting on this pendulum see the mathematica demonstration on forces on a pendulum.

This similar demonstration illustrates the forces acting on a bob as it swings. Notice how the direction of the net force acting on the bob reverses direction once the bob passes the minimum point of its swing.