Ch. 18: Forms of Energy

Vocabulary:energy, mechanical energy, light, heat,

sound, vibrate, chemical energy, electrical energy, energy transformation

What is Energy?

• Energy is the ability to do work or cause change.• Work means moving an object from one place to

another place.• Energy is different from matter.• Matter is made of atoms, energy is not made of

atoms.• Energy does not take up space, or have mass.• Energy makes things happen.• Energy comes in many forms.

Mechanical Energy

• Mechanical energy is the energy of moving objects.

• Anything that moves is using mechanical energy.

Light Energy

• Light is energy we can see.

• It moves from place to place in waves.

• It comes in many colors.• All the colors of light

put together make white light.

Heat Energy

• Heat energy makes things feel warm.

• Most things that give off light, also give off heat.

• Heat energy moves from objects with more heat to objects with less heat.

• There is no such thing as cold energy.

• You feel cold when you touch matter that does not have much heat in it.

• The more cold something feels, the less heat it has in it.

Sound Energy

Guitar Strings Vibrate When Plucked

Plucked Guitar Strings Make Sound Travel

in Waves – Different Sounds Look Like Different Types of Waves

• Sound is energy we can hear.• Sound is made by vibrations.• Vibrations are caused by objects

moving back and forth.• When someone plucks a guitar

string, it makes the string vibrate.• The vibrating string makes the air

around it vibrate.• The vibration in the air moves

until it comes into contact with the air in your ear, which begins to vibrate.

• The vibrating air in your ear makes small parts in your ear vibrate, which passes through nerves to your brain.

Chemical Energy

• Energy that can be stored is chemical energy.

• Fuels, like oil, coal, and natural gas are chemical energy.

• Chemical energy can also be found in batteries.

• Chemical energy can also be found in food.

Electrical Energy

• Electrical energy is the energy of moving electric charges.

• Electricity moves from the power plant through wires into your home.

• Just about everything we own is powered by electricity in some way.

• Also, lightning is made of electricity.

Energy Transformations

• One form of energy can be changed into another form of energy.

• When energy changes it transforms into another form of energy.

• This is how we are able to use energy.• The chemical energy in batteries is transformed into

electrical energy when you put them in a flashlight, then transformed again into light energy when it comes out of the bulb.

Questions About Chapter 18

1. What is energy?

2. What are the six different kinds of energy?

3. Which type of energy is produced by vibrations?

4. Which type of energy can be stored to use later?

5. Give an example of mechanical energy.