Show a video demonstrating how hydroelectric plants utilize the kinetic energy of a waterfall to create electrical energy. While it may not be cost effective to take the students to a plant in person, a TV and DVD player can help get the idea across and the students can still see how everything works.
Introduce a "shake and shine" flashlight to the class and show that it does not have a charge and will not turn on. Shake it up and down for a moment and pass it to each student to do the same. After the last student has taken his turn shaking it, turn off the lights and turn on the flashlight. The light should now be bright enough to illuminate the room temporarily.
Explain how the flashlight works. Magnets generate electricity along a wire coil as it moves across it. The motion is needed to electrify the entire wire and the magnet only powers it when moving in one direction.
Demonstrate how a self-winding watch works and pass it around for students to examine. The motion of the user's arm helps to wind the mainspring which then powers the watch hands.
Discuss other applications of kinetic energy, including how it can be used to benefit soldiers in the field since it helps reduce the need for carrying batteries, which are heavy and sometimes inefficient. Answer any questions the students have.