Did You Hear That?

1. Did You Hear That? By Andrew Cobb & IonutAlbu

2. The “Screaming” Balloon • What made the balloon “scream”? • Key Question: • What is sound, how is it made and transferred?

3. Tuning Fork & Ping Pong Ball • DO NOT HIT THE TUNING FORK ON YOUR DESKS. ONLY USE THE PALM OF YOUR HAND. • One group member hit the tuning fork, another touch the ping pong ball to the tuning fork • Be sure to make a prediction before you start the experiment • Let each member of the group give it a try

4. Tuning Fork & Water • Hit the tuning fork (again only using your palm) and place it in the water • Be sure to only put the tuning fork in about half an inch • Don’t touch the tuning fork to the side of the glass, this will mess up your results

5. The “Clucking Chicken” • Be careful with how you pull on the string • Try it first without wetting the sponge, holding the cup • Then try it with a wet sponge, holding the cup • Then, while also using a wet sponge try it holding the string and not the cup

6. Sound Wave Wavelength Amplitude

7. Wavelength and Frequency Short Wavelength Long Wavelength

8. Pitch • Pitch makes a sound “high” or “low” • Depends on frequency • Objects with less matter vibrate faster • Faster vibration = Higher frequency • Higher Frequency = Higher pitch • Objects can vibrate or the air inside of them, this affects the kind of pitch you get.

9. Predict Pitches for each Bottle:Struck ✓ ✓ ✓

10. Predict Pitches for each Bottle:Blown ✓ ✓ ✓

11. Review • Sounds • are made by vibrations. • travel as waves. • Waves • have energy. • are measured from peak to peak or trough to trough. • Frequency measures the number of vibrations in one second. • Pitch • How “high” or “low” a sound is and depends on frequency