UP & DOWN? SIDE TO SIDE?

Another way to categorize waves is by the way particles in the wave move.

Below are two type of waves. With a partner, please play with these two models. Try out all the buttons, and try changing the color of some of the dots by clicking on them.

Using the focus words and other academic language you know, attempt to describe what you observe as the same or different when examining these waves. Use your own lab book or click here for a template (Google Doc).

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Do you remember the terms perpendicular and parallel from math class? Click here if you forgot.Now you'll be using the concepts of parallel and perpendicular to identify Wave Model A and Wave Model B by their scientific names.

Here is a definition of a TRANSVERSE wave:

A transverse wave is a wave in which particles of the medium move in a direction perpendicular to the direction that the wave moves.

Here is a definition of a LONGITUDINAL wave:

A longitudinal wave is a wave in which particles of the medium move in a direction parallel to the direction that the wave moves.

So, which model represents which type of wave?

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Act it out!?

We've all seen waves like the ones below at sports events live or on television.

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Is this an example of transverse or a longitudinal wave? Explain your thinking to your partner.

Option 1: With a group of your classmates, act out a wave like in the model above. When you're ready, go in front of the class to demonstrate.

BONUS: Students watching will be able to ask your group to increase or decrease the wave's frequency, wavelength, or amplitude. Good luck!

Option 2: Figure out a safe way to act out a longitudinal wave with people. When you're ready, go in front of the class to demonstrate. Be sure to show the compressions of the wave.

BONUS: Is there is way to increase and decrease the wave's frequency?

 

Water Wave Model

Below is a model of the surface of water waves. Examine the model closely and observe the motion of the dots. Are water waves transverse? Longitudinal? Or maybe something else? Come up with the best description you can.

 

When you think you have a good idea, look at Dan Russell's website from Penn State University. Observe his model of water waves and read his explanation. Was your idea on the right track? Also compare his other models to the ones you have worked with previously in this unit. Notice anything different in his models?

 

Sometimes people get the wrong idea about water waves when watching surfers. They think that since a surfer is moving quickly toward the shore, the water must also be moving toward the shore along with surfer. Use the model below to begin constructing a theory about why the beach ball and the surfer interact with the wave so differently. This is tricky! Good luck! Be ready to present your thinking during a class discussion.

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Why do waves break at the beach?