1. Waves

2. How many waves can you identify?
You have just returned home from a day at the beach. You are hungry from playing in the ocean under the hot sun. You microwave some left over pizza. The phone rings, and you turn on the radio.
List all the waves in your new packet p 2.

3. What is a wave?
A wave is a disturbance that transmits energy through matter or space.
A medium is a substance or material which carries the wave.

4. P 3 Packet
What is the difference between a mechanical wave and an electromagnetic wave?

5. Energetic Waves
Tie a rope to the back of your chair. Hold the other end so that it is almost straight but not tight.
Move the rope up and down quickly to create a single wave. Record your observations on the left side of your INB.
Which direction does the wave move?
Compare the movement of the rope with the movement of the wave.
Where does the energy come from?

6. Put a piece of tape on the rope
What direction does the tape move? Is it in the same direction as the wave? Observe in INB
Energy can be carried from its source by a wave. But the material does not move with the energy.
Ex leaf on water, sound in air.
Which direction does the wave move?
Compare the movement of the tape with the movement of the rope with the movement of the wave.
Where does the energy come from?

7. Do Now
How are light and sound alike? How are they different? Use your Nature of Waves packet to help you.
On 2 pages (p 4) of your packet, make a gigantic Venn diagram comparing the two.
Light Sound

8. Two kinds of waves Longitudinal Transverse
Read Types of Waves, p 6-9, highlight 3 of the most important things for each type of wave.

9. Longitudinal
Vibrates parallel to (in the same direction of) wave travel – The “LONG” way
For example: sound waves
The other end of the medium moves without the actual movement of matter.
Animation courtesy of Dr. Dan Russell, Kettering University

10. Animation courtesy of Dr. Dan Russell, Kettering University

11. Longitudinal Use your Slinky to demonstrate a longitudinal wave:
Work with a partner
Stretch it out along the table
One of you grasp and draw several coils of a stretched Slinky toward yourself
Release the coils
The other student must hold his or her end of the Slinky still
A longitudinal wave pulse will be generated and travel down the length of the Slinky.

12. Longitudinal Are composed of
Compressions, where the parts of the medium (coils of the Slinky) are closer together than normal
In this investigation, you created (generated) compressional longitudinal waves
The waves traveled through a media (the slinky)

13. Longitudinal Use your Slinky to demonstrate a longitudinal wave:
Work with a partner
Stretch it out along the table
One of you stretch a segment of the Slinky
Release the coils
The other student must hold his or her end of the Slinky still
A longitudinal wave pulse will be generated and travel down the length of the Slinky.

14. Longitudinal Are composed of
Rarefactions, where the parts of the medium are farther apart than normal
In this demonstration, you created (generated) rarefactional longitudinal waves
The waves traveled through a media (the slinky)

15. Transverse Vibrates perpendicular (at right angles) to the wave travel
An example of transverse waves are Electromagnetic waves. Trans means across.
Animation courtesy of Dr. Dan Russell, Kettering University

16. Transverse Use your Slinky to demonstrate a transverse wave:
Work with a partner
One of you move your end of the Slinky back and forth (left and right, like a snake crawling), perpendicular to its stretched length.
The other student must hold his or her end of the Slinky still
A series of transverse waves will be generated and will travel through a medium (Slinky)

17. Reflection Complete your Venn diagram comparing
transverse waves and longitudinal waves.

18. Electromagnetic Waves
Are waves which are capable of transmitting its energy through a vacuum (i.e., empty space)
Produced by the vibration of electrons within atoms on the Sun's surface
Travel through space until they reach Earth
Examples are light and heat
Are transverse waves which mean the particles vibrate ACROSS the direction of the wave

19. Mechanical Waves
Are not capable of transmitting their energy through a vacuum (space)
Require a medium in order to transport their energy from one location to another
Sound waves are mechanical longitudinal.

20. Mechanical Waves
Waves traveling through a solid medium can be either transverse waves or longitudinal waves.

21. Water Waves A combination of longitudinal & transverse
Animation courtesy of Dr. Dan Russell, Kettering University

22. DO NOW
Sometimes people at a sports event do “the wave”. Do you think this is a real example of a wave? Why or why not? Quick Write on p 2.

23. Parts of a Wave

24. Read and Learn
Read the Nature of Waves handout p and define wavelength, amplitude, and frequency in your notes on p 5 of packet.
Crest, trough and rest position are also important terms.
HSTP480, HST490

25. Parts of a Wave Wavelength –
In transverse waves – distance between two crests or troughs
In longitudinal waves – distance between two compressions or rarefactions
Frequency – the number of waves that pass a point in one second
Long wavelengths have low frequencies
Short wavelengths have high frequencies
Amplitude (wave height) – the distance from the middle of a transverse wave to the crest or trough

26. Change amplitude!
Hold a slinky on the floor between you and your partner. Move one end from side to side at a constant rate. The number of times you move it from side to side is (back and forth) each second is the frequency.
Keeping the frequency the same, increase the amplitude. How did the change in amplitude affect the wavelength? Record in packet.

27. Change frequency!
Now shake the slinky back and forth twice as fast (double the frequency).
What happened to the wavelength?
Record in packet.

28. Summary
Write 3 sentences showing how each property changes the other: use the terms frequency, amplitude and wavelength.