How can so many different sounds be coming from the needle and the record when you spin it?
- Do Now- Copy down today’s homework assignment in your planner. Get out your ISN and add to the Table of Contents- “Investigations 1-3 p.31” (Right Side); Head page 31 properly with “Invetigations- 12/4/17.”
- Talk with your cooperative table group– How do the vibrations from sound sources compare when they produce louder vs softer sounds? How do the vibrations from sound sources compare when they produce higher vs. lower pitch sounds? What makes the needle on the record vibrate as the record is spun?
- Write-Pair-Share- Individually, write your answer to the following question on ISN p.31. Use complete sentences. If differences in the volume of a sound and differences in the pitch of a sound are due to differences in the amplitude & frequency of vibrations, then wouldn’t something in the grooves of the record be making the needle vibrate at different frequencies or deform with different amplitudes so that it produced different sounds? What might be forcing it to change its pattern of vibration? Pair to share your answers with your cooperative table group and then the whole class.
- Investigations 1-3- Let’s look at the record and needle again to see if its vibrations are changing as it produces different sounds…We’ll look again at the Michael Jackson video of the closeup of the needle on the record. This time, look to see differences in the frequency or amplitude of the vibrations of the needle as it produces sound. Answer questions Q3-Q6 in handout. Look through the procedure for Investigation 2. Complete it with a partner. When you are done with Investigation 2, send one partner to the demonstration desk to get a copy of the photograph of the surface of the record. You will be able to write, label, & draw on this photograph so be prepared so share your findings.
STUDY for the Sound Source Quiz on Wed. 12/6– ISN pages 15-31