A Simple pendulum reactive physics model using Unity and Rigidbody Mechanics
Create your pendulum 3d object or primtive sphere type with a Rigidbody Component and Add the PendulumBehaviour script onto it. You can also use the Wire script to create a mesh procedurally for the physical wire that connects the pendulum bob to the top.
A camera movement script it also provided to pan and rotate around the pendulum appropriately.