Waves

Waves

Mrs. Erwin

Surf's up bruh!

DEFINITION OF WAVES

Waves are a pattern of motion that transfer energy from place to place

 without transferring matter. There are different types of waves.

 Sound waves travel through air and allow us to hear sound. Water waves

 move on top of water. Light waves move in straight lines through space.

For now we will focus on sound and water waves.

Energy travels through waves.

Waves transport energy, not matter, from place

to place. Remember that matter is made of particles too small to be seen.

Particles or a (medium) are required to transport some types of waves, such as sound waves. 

When the wave travels, the particles do not travel with the wave.

It may appear that ocean waves are moving particles of water

toward you, but in fact, the water is only moving up and down.

We can test this by placing a heavy

 ball in a wave tank. 

The waves move from one side of the

 tank to the other, but the ball does not

travel, it only moves

 up and down

Multiple Choice

What do waves carry from place to place?

• Energy, but not matter or particles

• Energy and matter or particles

• Matter or particles but not energy

• Neither energy nor matter or particles

Transverse Waves

Scientists put waves into two general 

categories: transverse waves and longitudinal waves. Transverse 

waves vibrate perpendicular to 

the direction that the wave travels. 

Ocean waves are a great example

of a transverse wave. “The wave” 

at a sporting event is also a transverse

 wave.

Multiple Choice

What do the people in the video represent in the "wave"?

• The people are the medium that the energy passes through.

• The people are the energy that is traveling?

Multiple Choice

Which is a Transverse Wave?

Longitudinal Waves

Longitudinal waves vibrate in the same 

direction that the wave travels. 

Picture standing at one end of a 

spring toy, with a friend holding the

other end. If you pull your end and let 

go, you will create a compression in the spring that travels down its 

length. Sounds waves are an example

of longitudinal waves.

Multiple Choice

What type of wave is this?

• Longitudinal

• Transverse

• Electromagnetic

• x ray

Multiple Choice

In a longitudinal wave, the parts where the coils are far apart is called_________.

• longitudinal

• compressions

• rarefactions

• contractions

Multiple Choice

In a longitudinal wave, the parts where the coils are close together are called what?

• longitudes

• rarefactions

• compressions

• contractions

Amplitude is the height of the wave.

• Amplitudeis a measure of the wave’s

  height. It also tells us how much energy a wave has. Waves with more  energy have higher amplitudes.

• The amplitude of a sound wave determines the sound’s loudness. When you turn the volume up on the TV, you are increasing the amplitude of the sound waves.

Multiple Choice

Amplitude reflects the amount of ____________________ in a wave.

• energy

• compression

• rarefaction

• speed

Wavelength is the 

distance between wave crests

Wavelength measures the distance 

between wave crests. The closer the 

crests of the wave are to each other, 

the more energy the waves have. 

The opposite is also true: 

when the wavelength is longer, the 

waves have less energy.

Multiple Choice

A _____________________ is the distance between a point on one wave and the identical point of the next wave.

• amplitude

• wavelength

• frequency

• compression

Sound waves travel through the air.

Sound waves are caused by vibrations. 

Since air is made of particles (matter), it transports sound very well.

When a speaker vibrates it creates longitudinal waves that travel in 

ALL directions.

You can easily see how speakers 

create vibrations by sprinkling

 something small and light, like 

sand, onto a speaker. The sand 

particles will bounce due to the

vibrations. 

Since sound waves travel in all 

directions you can hear sound even 

when you are not directly in front of 

the source.

Open Ended

What happen to the the salt when they played different frequencies?

Multiple Choice

Sound is caused by? 

• force
• vibrations
• instruments
• medium

Amplifiers make music louder. 

Rock stars use electronics to increase

 the amplitude of their sound waves. 

That means they use electricity to 

make the speakers vibrate with more 

energy, which increases the amplitude. 

Rock on!

Poll

Mrs. Erwin rocked that guitar!

• Yes she did! That was cool!

• She's okay!

• I could do better!

Most of the sounds we hear travel through the air, but sound can also travel through solids and liquids too. Some solids, like metal and glass, 

are good at transmitting sounds. Other solids, including heavy fabrics and 

foam, muffle sounds. Sound can also move through liquids. Some animals, 

such as dolphins and whales, communicate with each other underwater by using sound waves. We call that "echolocation."

Multiple Choice

What is echolocation?

• The way bats fly.

• The noise dolphins make underwater.

• High-frequency sounds

• The food rabbits eat.

Multiple Select

Echolocation helps animals do what 3 things ... (Click all that apply)

• Locate food

• Sleep better

• Navigate

• Avoid predators

Sesmic Waves

Earthquakes travel as waves too.

Earthquakes can transmit so much 

energy that they topple buildings and 

destroy property. By understanding 

how these waves travel we can warn 

people when there is an earthquake 

in their part of the world.