1. The Behavior of Mechanical Waves
Unit 1-Lesson2

2. Standards Covered:
MS-PS4-1: Use mathematical representations to describe a simple model for waves that includes how the amplitude of a wave is related to the energy in a wave.
MS-PS4-2: Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.

3. Session 1: Mechanical Waves
Objectives
I can explain how the behavior of mechanical waves corresponds to the properties of waves.
I can identify different media that carry waves.

4. What is Echolocation? / Brain Wave Episode 5
Watch the following video and fill the provided transcript on your notebooks.
Link:

5. In the video you saw dolphins swimming through waves in the ocean
In the video you saw dolphins swimming through waves in the ocean. They communicate with each other using sound waves that travel through water or air. They can even use sound waves to find food.
What else did you see in the video? (Answer briefly)

6. Can You Explain It? T.B. Page 23
Humans and many other animals use light to see, but there are other ways to observe the world. Some animals, such as bats and dolphins, can also use mechanical waves to visualize the world around them. The adjacent image is a map of a sea floor that was created using mechanical waves.
When a mechanical wave, such as sound, reflects off a surface, what can you the reflected wave tell you about the surface?

7. Exploration1-Investigating Mechanical Waves
Tsunamis are huge waves that carry large amounts of energy across the ocean.
They are often caused by underwater earthquakes.
Once a tsunami forms, the wave can travel hundreds of kilometers before reaching land.
Are the water molecules that touch the land the same ones that the earthquake initially moved?
Why and why not?

8. Mechanical Waves
Label the medium that each mechanical wave is passing through.

9. TASK # 1-Individual Work
“Select a type of wave that you are familiar with. Determine where the initial energy of the wave comes from and what medium the wave travels through.
Sketch the medium of the wave and the initial energy input.”

10. Lab Session -Objectives
I can generate and observe mechanical waves in different types of media.
I can propose ways to observe amplitude, frequency, and speed of the wave as it travels through material.

11. Lab Activity: Generate Mechanical Waves

12. Lab Activity: Generate Mechanical Waves

13. Lab Activity Evaluation:
Consider this activity in a larger context and answer the following questions:
How are waves generated?
What kinds of media can waves travel through?
What happens to a wave’s shape when it travels?
What happens to the energy of a wave as it travels?

14. Session 3: Sound, Media, and Wave Speed
Objective:
I can explain how the wave’s speed changes as it travels in different media.

15. TASK # 2-Group Activity:

16. Instructions: Group 1 –Blue Group
List the types of media that a sound wave needs to travel.
In what state of matter of matter does sound travel fastest?
Group 2- Green Group
Explore: Why does the speed of sound change from one state of matter to the other?
Group 3-Violet Group
Do the Math: Use the table to calculate and compare the average speed of sound in a gas, a liquid, and a solid, to the nearest m/s.

17. Complete Sound, Media, and Wave Speed Worksheet
TASK # 2-continued
Present your work.
Complete Sound, Media, and Wave Speed Worksheet

18. Session 4: Properties of Sound
Objectives:
I can use a model to explain how different sound interact with different media.

19. Frequency and Pitch
Use the information provided in the following video to answer the following questions in your notebook:
Video: The Physics of Sound Amplitude and Frequency
Link:
1) What does the pitch of the sound wave refer to?
2) How is the frequency of a sound wave related to its pitch?

20. TASK # 3-Group Work
When you listen to music from a musical instrument, how does the sound reach your ear?
Use sketches, labels, and description to show how the sound wave moves from the instrument, through air, toward a listener’s ear.
Be sure to describe any particle movement that occurs.
P.S. Use the links and resources provided in your instruction sheet.

21. To Be Continued