Physics of Sound
Investigation 1
Part 3
Sound and Vibrations
Students observe that vibrations cause sound. Students experiment with volume by intensifying vibrations of a tuning fork and other instruments.
3. Lesson set up and Management
Wave Behavior: Describe experience with sound, for example, vibrations, echoes, and pitch. (PC01 1.1.3)
Sound is caused by vibrations.
A sound source is an object that is vibrating.
Changing the amplitude of a vibration changes volume.
3. Lesson set up and Management
Materials:
Make copies of Student Sheet No. 4 called Tuning Fork and Student Sheet No. 5 called The Long Gong.
Prepare and practice with the miniactivity equipment.
Tie one end of the rope to the donut shaped piece of wood and secure it under the door prior to wrapping the rope and attaching it to the handle. Practice setting up and using the Door Fiddle so you feel comfortable assembling it in front of your students. |
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Be sure to practice with the Tone Generator so you understand how it works before you demonstrate it to your students. Check to see if the batteries are strong enough to power it. |
Check your kit to see if the Long Gongs are assembled. If not, it may be a good idea to assemble them for your students. Students can spend less time in preparation and more time in exploration since this can be a lengthy activity. The wire of the Long Gong must hang freely in order to vibrate and the cup must be held up around the ear. Test them once you have built them. They work remarkably well! |
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Remember to strike the tuning fork on the wooden block or your shoe and demonstrate this to your students. Be sure to strike only one prong of the tunning fork on the wooden block. Keep in mind that students will need more practice than you. |
Try the different steps to the Tuning Fork activity to find out just how much water a vibrating tuning fork can displace. |
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Student Management:
Your students may do best if you break this part of the investigations up into two sections. You may want to share the Door Fiddle and the Tone Generator on one day and have students work in groups with the Long Gong and Tuning Fork activities on another day.
There are enough materials for half of the class to explore the Long Gongs and half the class to explore the Tuning Fork activities at the same time. Students should work through these activities by reading and following directions on the student work sheets.
You may need to set a ground rule in place so students will not get carried away with the tuning fork and the water, perhaps once or twice per person.
These investigations can become noisy. Try to schedule this part of the activity during a time that will allow your students to explore without disrupting nearby classrooms.
Be sure to practice using the Door Fiddle and test the batteries in the Tone Generators. This will take a few short minutes and save your lesson.
Writing Support:
In this activity it is important that student’s reflections are focused on sound as vibration and on loud and soft sounds. Encourage students to use the word 'volume' in their writing. Use Student Sheets No. 4 and 5 or the writing prompt, “Explain how you can tell vibrations cause sound.”