Subject: Science   

Topic: Sound - The Relationship Between Pitch and Vibration.

Outcomes:  Students will be able to explain the relationship between pitch of sound and vibration.

Learning Activities:  

1.   Review and define the term pitch as related to sound.

2.      Discuss the Law of Conservation of Energy, which states that energy cannot be created or destroyed, only converted from one form to another.  Students need to understand that sound is a form of energy.

3.      Have students predict the relationship between the pitch of sound and its frequency of vibration (rapid or slow). Record the prediction.

4.      Students test the prediction by building a Soundsensor by following this procedure:

a.       Blow up the balloon and release it a few times

b.      Cut off the long stem of the balloon

c.       Fasten the balloon over one end of the tin can making sure it is tight like a drum.

5.      To use the sensor hold the can about 10 cm from your mouth     and speak into the open end of the can while holding your finger very gently on the balloon.  Record what you feel.

6.      Make a sound and hold it as long as you can.  Do you feel any difference when you make a sound with a low pitch as compared to a sound with a high pitch? 

Evaluation: Answer the following questions. 

1. What relationship did you observe between the pitch of the sound and its frequency of vibration?
2. Did this differ from your guess? Explain.
3. What causes the balloon to vibrate?

Reference:  NetWorks Understanding Telecommunication Kit.  This is one lesson in a classroom resource designed to allow students to investigate how telecommunications works.