Forms of Energy

​Newslea: How Energy is Transferred
By National Geographic Society, adapted by Newsela staff on 09.12.19
Word Count 493 Level 470L

​Install Google Slides Extension

​Image 1. Newton's cradle is a device that demonstrates the transfer of kinetic energy. Photo from: Wikimedia Commons

​Energy is ability to do work. It cannot be made. It cannot be destroyed. Energy can change form. It can move between things as well. Moving energy between things is called energy transfer. Something moving has energy. You can transfer its energy to something still. Say a bat hits a ball on a tee. Some of the bat's energy moves to the ball. It stays the same kind of energy. The ball now has energy to move.

Multiple Choice

What is energy's ability?

• 
  To be created

• To be destroyed

• To do work

• To disappear

Multiple Choice

What happens when a bat hits a ball?

• 
  The ball loses energy

• The ball gains energy

• The bat loses energy

• The bat gains energy

Thermal nergy Moves in Three Ways

Thermal energy comes from how hot something is. "Heat" means thermal energy moving from something hotter to something cooler. Thermal energy can transfer in three ways: conduction, convection and radiation.

Multiple Choice

What does "heat" mean in terms of thermal energy?

• Energy moving from cooler to hotter

• Energy staying still

• Energy moving from hotter to cooler

• Energy disappearing

Multiple Choice

How many ways can thermal energy transfer?

• One

• Two

• Three

• Four

Conduction is thermal energy moving between molecules that are touching. Place a metal spoon in boiling water. The end not touching the water gets hot. This happens because metal is good at carrying heat. Some things, such as wood, are not good at carrying heat. They are called insulators.

Fill in the Blanks

What are materials called that are not good at carrying heat?

Convection only happens in liquids and gases. When water boils on a stove, molecules at the bottom are closest to the heat. They move faster. They move apart. Then they rise up. Cooler water goes to the bottom. This makes a current of molecules. They are sinking, heating up, moving up, cooling down and sinking again.

Multiple Choice

What happens to the molecules when water boils?

• the molecules move faster

• the molecules move slower

• the molecules disappear

• the molecules move into the air

The third kind of heat transfer is called radiation. With radiation, a heat source does not have to touch the thing being heated. Take the sun. Nearly all thermal energy on the planet comes from the sun. It moves as energy waves, such as light.

Multiple Choice

What is radiation?

• Heat transfer through liquids

• Heat transfer through waves like light

• Heat transfer through direct contact

• Heat transfer through solids

​Energy Changes Form

Energy can change form, too. This is called transformation. Think of a ball on a hill. It has stored energy because of where it is. This energy is called potential energy. Something with potential energy can do work because of its position. Say the ball rolls down the hill. Then its potential energy changes into kinetic, or movement energy.

Multiple Choice

What is potential energy?

• Energy in motion

• Energy from the sun

• Energy stored because of position

• Energy from food

Multiple Choice

What happens to a ball's energy when it rolls down a hill?

• It turns into kinetic energy

• It turns into potential energy

• It disappears

• It stays the same

The ball stops at the bottom of the hill. That's because of friction. Friction is a push or a pull. It pulls on things moving past each other. Friction changes the ball's kinetic energy into heat. The amount of energy stays the same in transformations

Fill in the Blanks

What causes a ball to stop at the bottom of a hill?

​How Energy Moves Around A Sand Dune

Energy transfers and transformations happen all the time. Let's look at sand dunes. Thermal energy shines from the sun. It heats the land and sea. Water heats more slowly than land. This makes a convection current in the air. The current makes wind. This wind has kinetic energy. It carries sand a short way. This energy transfers to the sand. If the sand hits something, friction stops it. Sand builds up. Dunes are made. Plants grow in the dunes. They use light to store energy as sugar. Animals eat the plants. They use the sugar's energy to move and heat their bodies. Energy transfers and transformations happen constantly. They allow life to exist.

Multiple Choice

What allows life to exist according to the text?

• Energy transfers and transformation

• The sun's light

• Essential The presence of water

• The moon's gravity

Multiple Choice

What do animals do with the energy from plants?

• They turn it into water

• They release it into the air

• They use it to move and heat their bodies

• They store it in the ground

Multiple Choice

What happens when wind carries sand?

• The sand disappears

• The sand builds up to form dunes

• The sand melts

• The sand turns into water

Multiple Choice

How do plants use light in sand dunes?

• To store energy as sugar

• To create wind

• To create wind

• To create water