Write these sentences in your own words: kinetic energy is the energy of motion, observable as the movement of an object, particle, or set of particles. any object in motion is using kinetic energy: a person walking, a thrown baseball, a crumb falling from a table, and a charged particle in an electric field are all examples of kinetic energy at work. objects that are not in motion possess potential energy (the other main type of energy), which is converted to kinetic energy when some force , such as gravity , acts upon the object to set it in motion. elastic potential energy, for example, is stored in a stretched rubber band; when the rubber band is released, the stored energy is converted to kinetic energy.