Sound

Question 1

What are the two components of sound?

Answer 1

• displacement component: molecule displacement

- pressure component: molecule compression

Question 2

Why is sound pressure level important?

Answer 2

• different animals have different thresholds
• humans is at 20db
• must use animals threshold for accurate experiment

Question 3

What causes a sound to be louder?

Answer 3

• greater membrane movement = greater amplitude

- greater amplitude = louder

Question 4

What causes a high pitch?

Answer 4

• greater frequency of membrane movement

Question 5

How is wavelength found?

Answer 5

• plotting distance vs pressure and measuring from peak to peak
• wavelength (lambda) (m) = speed of sound in medium (m/s)/ frequency(s-1)

Question 6

What component of sound is most important for propagation?

Answer 6

• propagation occurs by chain reaction of molecules
• displacement dissipates quickly
• pressure can be detected over long distances

Question 7

What causes a reduction in pressure as sound travels?

Answer 7

• spherical spreading: must cover more space

- can also be reflected, diffracted, absorbed and transmitted

Question 8

How do light and sound compare?

Answer 8

• both use wavelength and frequency ad exhibit ability to be diffracted, reflected..
• light is described by wavelength and is an electromagnetic wavelength
• sound is described by frequency and is a mechanical wave

Question 9

What happens to an echo when different sized objects produce them?

Answer 9

• large object (bigger than wavelength) will produce strong echo
• small object (smaller than wavelength) will produce no echo
• an object slightly greater than one wavelength will produce echo and sound shadow