Force, Energy, Motion

• Energy is invisible but can be observed when children are running on the street, a light from a lampshade, a sound from the radio, or feeling the heat of the sun
• All living and non-living things need energy
• Energy warms the planet and makes life possible
• Energy enables people to do household chores, work in school, illuminate homes, operate appliances, and move cars
• In physics, energy is described as the ability to do work or make changes
• Energy can be classified into two types: kinetic energy and potential energy
• Potential energy is energy stored in an object at rest
• Kinetic energy is energy in motion
• Forms of energy include mechanical energy, heat energy, light energy, sound energy, and electrical energy
• Mechanical energy is the sum of potential energy and kinetic energy
• Examples of mechanical energy include windmills, falling water, dancing, playing, doing exercises, and moving cars
• Electrical energy is possessed by moving electrons that light bulbs and power appliances
• Examples of electrical energy include electric circuits, lightning, transmission lines, and turned-on appliances
• Chemical energy is stored in bonds of chemical compounds like atoms and molecules
• Examples of chemical energy include batteries, food, fuel, matchsticks, fireworks, and medicines
• Heat energy is energy in transit transferred from one body to another
• Examples of heat energy include a spoon becoming hot in hot soup and pork becoming cooked near fire
• Sound energy is produced by vibrating objects
• Examples of sound energy include radios, televisions, cell phones, and musical instruments
• Radiant or light energy is a form of electromagnetic radiation produced by hot objects that can be seen by the human eye
• Examples of light energy include sunlight, light bulbs, candles, lasers, fire, and flashlights