Sound

Question 1

how is sound produced?

Answer 1

by vibrating sources placed in a medium

Question 2

how does longitudinal waves propagate?

Answer 2

as a series of compressions and rarefactions

Question 3

what are compressions?

Answer 3

regions where the medium’s density is higher than the surrounding density

Question 4

what are rarefactions?

Answer 4

regions where medium’s density is lower than surrounding density

Question 5

describe how a sound wave produced in air by vibration of a tuning fork

Answer 5

1. layers of air are in undisturbed positions
2. when the prongs push outwards, a region of compression is produced
3. when the prongs move inwards, a region of rarefaction is produced
4. prongs continue to vibrate (moving inward and outward)
5. a series of compressions and rarefactions is set up

Question 6

does sound require a medium?

Answer 6

sound needs a medium to travel from one point to another. travels at different speeds in different media

Question 7

sound travels…

Answer 7

fastest in solids, slowest in gas.

Question 8

why does sound travel fastest in solids?

Answer 8

particles are most closely packed together in solids, easier to transfer energy by vibration when particles are closer together.

Question 9

what is an echo?

Answer 9

the repitition of a sound due to reflection of sound. it is formed when sound is reflected off hard, flat surfaces.

Question 10

echoes used to:

Answer 10

• measure large distances
• detect the location of objects by the method of echolocation

Question 11

how to calculate speed of echoes?

Answer 11

2 distance/ time taken

Question 12

pitch

Answer 12

related to frequency of sound wave. higher frequency, higher pitch.

Question 13

loudness

Answer 13

related to amplitude of sound wave. larger amplitude, louder sound.