Energy Is a simply written, colorful reader that introduces young readers to a basic concept in physics. Energy is what is needed to do work. Work happens when force moves an object. Force is any action that changes the location, shape, or speed of an object. Food gives the body the energy it needs to do work. Energy comes in many forms, including food, batteries, and gasoline. A pronunciation guide for scientific terms is included. 24 full color, illustrated pages. Reading Level 1-3, Interest Level 2-5.