Define work as it applies to physics. Discuss a force is needed to move an object in the direction of the force. Introduce potential energy of location as gravitational potential energy. Determine that the force needed is equal to the mass times the gravitational constant. Elicit that as the mass increases, the gravitational PE increases. Discuss how a charged object can have a potential energy by virtue of its location in an electric field. Determine that when you push a single charge against an electric field, work is done and the electrical PE is increased