1. Chapter 26: Sound

2. What causes sound? The vibration of matter.

3. What type of waves are sound waves? Sound waves are longitudinal waves.

4. Can sound waves travel through a vacuum/empty space? No, because there’s no matter to vibrate.

5. Why do you see lightning before you hear the thunder? Because light travels much faster than sound.

6. From fastest to slowest, list how sound travels through solids, liquids and gases. Fastest through a solid Second fastest through a liquid Slowest through a gas (the air)

7. Does sound travel faster at higher temperatures or lower temperatures? Sound travels faster at higher temperatures.

8. What is resonance? Resonance occurs when something is forced to vibrate at its natural frequency resulting in an increase in amplitude.

9. What are some examples of resonance? Sound tube lab Causing a glass to “squeak” with your finger Tacoma Narrows Bridge collapse

10. Why do we use sounding boards in music boxes? To cause forced vibration in an object that has greater surface area. acoustic guitars, violins, pianos, etc

11. How can you determine how far away a thunder storm is? Time the seconds between the lightning bolt and thunder and multiply by 340.

12. What makes it possible for a singer to break a wine glass? resonance

13. What are the units of loudness/sound intensity? Decibels (dB)

14. How many times greater is a sound of 30 dB compared to a sound of 10 dB? 100 times greater (10 2 )

15. What causes beats? The interference of sounds waves that are produced by sources that are very close in frequency.

16. What is the frequency of beats when a 460 Hz and a 462 Hz tuning fork are sounded together? 2 Hz

17. Assuming that sound travels at 340 m/s. A batter hits the ball and you hear the crack of the bat one second later. How far away are you? 340 m

18. A legal firework shell explodes 680 meters away from you. How long until you hear it? 2 seconds

19. Sound waves travel 1500 m/s in water. If a 4 second time delay occurs for sound to travel to the ocean floor and back, how deep is the ocean? 3,000 m (one way)

20. What is the wavelength of a sound wave that has a frequency of 340 Hz? Remember, speed = 340 m/s Wave speed = wavelength x frequency So, wavelength = wave speed frequency 340 m/s 340 Hz = 1 meter

21. Can sound waves interfere so that there is no sound? Yes. Destructive interference cancels the sound

22. Why do different objects make different sounds when they hit the floor? Because they have different natural frequencies.