Chapter 5

Earth’s Energy

5.1 Energy Resources.

Lesson Objectives

• Compare ways in which energy is changed from one form to another.


• Discuss what happens when we burn a fuel.


• Describe the difference between renewable and nonrenewable resources, and classify
  different energy resources as renewable or nonrenewable.

Introduction

Did you know that everything you do takes energy? Even while you are sitting still, your
body is using energy to breathe, to keep your blood circulating, and to control many different
processes. But it’s not just you. Everything that moves or changes in any way—from plants
to animals to machines—needs energy. Have you ever wondered where all of this energy
comes from?

The Need for Energy

Energycan be defined as the ability to move or change matter. Every living thing needs
energy to live and grow. Your body gets its energy from food, but that is only a small part
of the energy you use every day. Cooking your food takes energy, and so does keeping it
cold in the refrigerator or the freezer. The same is true for heating or cooling your home.
Whether you are turning on a light in the kitchen or riding in a car to school, you are using
energy all day long. And because billions of people all around the world use energy, there
is a huge need for resources to provide all of this energy. Why do we need so much energy?