This resource provides an exceptional explanation of centripetal force. Explains why the common misconception of a centrifugal force is incorrect.

This site provides an introductory look at torque, the measure of how much a force acting on an object causes that object to rotate. Provides a definition of torque, illustrations, and also a formula to define torque.

In this simulation, examine the electric force that a charged particle gains from nearby charged particles in a two-dimensional state. See the net electric force shown as an arrow attached to the particle.