1. Introduction to Waves
Do you now have a grasp of the fundamentals of waves? What is wave motion? Can you distinguish between a longitudinal and transverse wave? What is the speed of light?
Follow the links (below) to answer these questions. Also, use the worksheets on Vibration and Waveform Graph and Wave Vocabulary to reinforce what you know.
Consider This Before Answering the Questions
Go to http://online.cctt.org/curriculumguide/units/waves.asp
and link to following information on Waves and Vibration:
After You Answer the Questions
After your review, move to the Worksheets menu at the top right and try your hand at the first two, Vibration and Waveform Graph and Wave Vocabulary. Because you don't have a student number for the site, print out the form and write in your answers, then compare your answers with those of other students in your class.
2. The Doppler Effect
Have you ever wondered about that shift in sound frequency as another vehicle is approaching and then passing us? How does the speed of sound differ when traveling through the three different media of gas, liquid, and solid? How does the speed of an airplane affect the sound? How do stationary and moving sound sources differ? What creates the sonic boom as a plane breaks through the sound barrier?
To explore the Doppler effect and sonic booms and to answer the questions above follow the links below.
Consider This Before Answering the Questions Visit http://library.thinkquest.org/19537/Physics4.html to get to the Think Quest site and then click on "The Soundry" link. Read about the speed of sound through the three different media of gas, liquid, and solid, then scroll down to click on the "I" to experience the Doppler effect for an airplane. Note that first they walk you through the simulation. Play around with the different speeds and look at the different waves. How does the speed of the airplane affect the sound? How do the waves differ? What happens when you move the figure, both before and during the plane's flight? Next go to http://www.kettering.edu/~drussell/Demos/doppler/doppler.html to learn more about the Doppler effect and sonic booms (have patience because it takes a while for all the graphics to load). Click on each of the links to get the full effect of Dr. Russell's efforts, beginning with the change in pitch of the car horn as it passes. Compare the Doppler effect with respect to both stationary and moving sound sources-how do they differ? After You Answer the Questions
At the end of this article, there are five (well, four, but the fifth is interesting) "Other important applications listed of the Doppler effect"-what are they and how is each important?
