S8-JU1L1 - Waves

Waves

S8-JU1L1

Poll

Space: noisy or not?

• Yes

• NO

What are some of the waves you can identify around you?

• Light waves from light bulbs, sound waves from people taking, radio waves making a radio signal are some of the waves all around you. 

Extend and reflect

Why can astronauts can hear each other in the space shuttle or in the space station if sound cannot be transmitted through space?

• The space station and shuttle are filled with air so that astronauts can breathe.

• Sound can travel through this air.

Have you ever seen or done "The Wave" at a sporting event? Is this more like a transverse wave or a longitudinal wave? 

• It is like a transverse wave because the people move up and down perpendicular to the wave as it passes by. 

Vocabulary

How are transverse and longitudinal waves similar and different? 

• Both types of waves carry energy.

• The particles in a longitudinal waves vibrate parallel to the direction the wave is moving, and the particles in a transverse wave move perpendicular. 

Do all waves need a medium to transmit their energy?

• No, electromagnetic waves can travel through space. 

What are some examples of EM waves traveling through empty space?

• Light from the sun, light from stars, radio waves and microwaves used in satellite communications all travel through empty space. 

What would we hear if radio waves were sound waves?

• If radio waves were sound waves, we would constantly hear all sorts of noise: all radio stations, and a constant background noise from radio waves that come from the sun and other stars.

• Astronomers use radio waves to locate and study stars.

Learning Alert

Are radio waves sound waves?

• No.

• Although we hear sound on a radio, they are two different types of waves. Radio waves transmit energy from the radio station to the radio, and then the radio changes the energy to sound waves that travel to our ears.

How do particles move as a wave travels through them? 

• Particles in a medium are disturbed, but they do not travel with the wave. 

Core concepts

How does the movement of the wave differ from the motion of the medium?

• The particles in a medium vibrate around their original positions as the wave moves forward. 

Extend and reflect

What is an example of a transverse waves? Of a longitudinal wave?

• Waves produced by shaking a rope are transverse, Sound waves are longitudinal.

Which direction to the particles vibrate in a transverse wave?

• Particles in a transverse wave move perpendicular to the direction of travel.

Through which type of medium do you think waves would travel the fastest? Why?

Waves would travel faster through a medium that transfers energy more quickly.

What is the difference between EM waves and mechanical waves?

• EM waves do not require a medium to travel through while mechanical waves do require a medium.

Synthesis

What do all wave types have in common?

• All waves transmit energy.

End of Presentation

Lesson 1 complete