Energy Conservation

Energy is the ability to do work. People use energy to walk and ride bikes, to move cars along roads and boats through water, to cook food on stoves, to make ice in freezers, to light our homes, and to send astronauts into space.

There are many different forms of energy, including heat, motion, electrical, chemical, or gravitational. The law of conservation of energy states that energy cannot be created or destroyed, but it can be transferred from one system to another and changed from one form to another. For example, the food we eat contains chemical energy. This energy is stored in our bodies until we use it. If we move when we play, we transform the chemical energy within our bodies into kinetic energy, the energy of motion. The kinetic energy of water flowing in rivers can be converted to electrical energy with an electrical generator, which in turn can be converted to light and heat. All of these are examples of energy being transformed and transferred but ultimately conserved.