Unit 3P Nature's Energies

1. What is Energy

Imagine . . . You’ve been swimming for a long time Friends ask you to play volleyball

You say you don’t have the energy What exactly do you mean? What is energy?

Vocabulary Energy The ability to do work

Moving things is a type of work When you hit a volleyball You move it!

Playing volleyball, jumping, and running all take When you jump and run You move yourself! Playing volleyball, jumping, and running all take ENERGY

There are several types of energy 1. Mechanical Energy When something moves It is using mechanical energy

Heat passes from one object to another 2. Heat Energy Heat passes from one object to another

3. Electric energy Electric energy is the flow of electrons which makes light bulbs light up and radios play.

4. Chemical energy When a chemicals are changed into mechanical energy with a chemical reaction

The mechanical energy moves the car A chemical reaction with the gasoline causes a change from chemical energy to mechanical energy The mechanical energy moves the car

Because it does not have mass Energy is not matter Matter takes up space Because it does not have mass or take up space

you can see what energy does You cannot see energy but you can see what energy does Each kind of energy can change into other kinds of energy

All the energy in the world comes from the sun The sun’s energy is called Solar Energy

On Earth, solar energy is changed into other kinds of energy Nothing on Earth could live without energy from the sun

Plants could not live without solar energy Plants make their own food

Plants make food out of water from the soil and gas in the air called carbon dioxide (CO2)

People eat the food that plants make Apples, potatoes, lettuce, celery, and beans are all plant foods that people eat

people would not have any Without solar energy, people would not have any plants to eat

Some animals also eat plants Animals eat other animals that eat plants

There would be no animals for Without plants, animals could not live There would be no animals for people to eat

You would not have chicken or hamburgers or fish to eat You would not have the things that animals produce, such as milk, eggs or wool

of the sun (solar energy) People and animals are warmed by the heat of the sun (solar energy)

When it is cold, people use fuels such as coal and oil to heat their homes. These fuels are made by solar energy

When the plants and animals died, their bodies became part of the Coal and oil were formed from plants and animals that lived millions of years ago (chemical energy) When the plants and animals died, their bodies became part of the Earth

The energy from these dead plants and animals became chemical energy in coal and oil

When coal and oil are burned, the stored chemical energy becomes heat energy