You will now create an outline for your final assignment.
In this lesson you learned about mechanical waves: what they are, how they are caused, how they transfer energy, and how they can be measured. You took notes on almost every page of the lesson, and now it's time to use them, as well as any other evidence presented, to compose your own multimedia project, or write a final essay, in which you describe and summarize all of that wave knowledge you've collected.
As you compose your project, try to think of ways to connect, either graphically or in writing, the ways in which the waves are related to each other. One idea would be to compose an infograph of a pyramid, with "Waves" at the top, and the types of waves underneath, with definitions, comparisons, and descriptions included.
If you create a multimedia project that requires a social-media, video, or audio platform that is not directly offered by this lesson, you will need to post it to a file-sharing site (Dropbox, Google Drive, and Microsoft Teams are examples) and then upload the link to the Write It plug-in. Here are some ideas for what you might want to do:
Use Organize It to outline your ideas. You can review your notes in “My Work” as well as any of the following videos and glossary terms.
| Keyboard Shortcut | Action |
|---|---|
| Space | Pause/Play video playback |
| Enter | Pause/Play video playback |
| m | Mute/Unmute video volume |
| Up and Down arrows | Increase and decrease volume by 10% |
| Right and Left arrows | Seek forward or backward by 5 seconds |
| 0-9 | Fast seek to x% of the video. |
| f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
| c | Press c to toggle captions on or off |
Waves are all around us. From the light we see, to the sound we hear, to the earthquake that shakes the ground. And the thing that makes a wave a wave is that it transports energy from one place to another. There are different types of waves (mechanical, electromagnetic) that transport energy through different environments (solid, liquid, gas, vacuum).
Sound, earthquakes, and waves in water are all mechanical waves meaning they use a medium -- actual physical particles -- to pass the energy along.
The birth of a mechanical wave starts with a disturbance. Energy is applied to the medium and the particles of that medium bump, push. or pull against one another. These vibrations transfer the energy from one place to another while the medium it is transferred through stays put. Although the particles move back and forth, or up and down, or around in circles, they don’t actually change locations. It’s only the energy that travels- and it can travel really, really far.
So when you hear that sound from afar, you can thank all the little particles that transferred that wave from there to here.
| Keyboard Shortcut | Action |
|---|---|
| Space | Pause/Play video playback |
| Enter | Pause/Play video playback |
| m | Mute/Unmute video volume |
| Up and Down arrows | Increase and decrease volume by 10% |
| Right and Left arrows | Seek forward or backward by 5 seconds |
| 0-9 | Fast seek to x% of the video. |
| f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
| c | Press c to toggle captions on or off |
Mechanical waves carry energy through a medium from one place (source) to another. But depending on the medium, the energy interacts with the particles in different ways.
Waves that move the medium up and down are called transverse waves. And waves that move the medium back and forth are called longitudinal waves.
Each of these waves has characteristics that can be measured to determine the distance between waves (wavelength), how fast the medium vibrates (frequency), and how intense (amplitude) the energy is.
First you have the wavelength, which is a measurement of the distance between one peak or one compression to another.
Then there is frequency, which is a measurement of how many waves go by in a period of time.
And the amplitude measures how intense the wave is -- how far each particle is getting pushed from its original resting place. The higher the amplitude, the more energy the waves are carrying.
So whether it’s a loud noise vs. a small or a big ripple vs. a little one, these waves all share certain measurable characteristics.
| Keyboard Shortcut | Action |
|---|---|
| Space | Pause/Play video playback |
| Enter | Pause/Play video playback |
| m | Mute/Unmute video volume |
| Up and Down arrows | Increase and decrease volume by 10% |
| Right and Left arrows | Seek forward or backward by 5 seconds |
| 0-9 | Fast seek to x% of the video. |
| f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
| c | Press c to toggle captions on or off |
A great place to see longitudinal and transverse waves in action is during an earthquake. When energy builds up in the earth’s crust, it is released during an earthquake by waves of energy traveling through the solid ground. These waves, called seismic waves, are examples of longitudinal and transverse waves and transfer energy in predictable ways.
The first type of wave that occurs and travels faster are called primary or P-waves. P-waves are longitudinal, meaning they compress and stretch the earth to move the energy outward.
Then, slower moving secondary, or S-waves, follow. These are transverse waves and transfer energy by moving the earth’s layers up and down, while moving the energy outward.
Both of these longitudinal and transverse waves transfer energy over long distances and can be measured (wavelength, frequency, amplitude) to determine the location of the source of the earthquake.