8. Sound

Question 1

what kind of wave is sound

Answer 1

mechanical longitudinal wave

Question 2

what mediums can sound travel through

Answer 2

any medium except a vacuum

Question 3

what is compression of sound

Answer 3

region of increased pressure on sound wave

Question 4

what is rarefaction

Answer 4

region of decreased pressure

Question 5

what will increasing the temperature do to the velocity of sound

Answer 5

increase velocity

Question 6

order the velocity of sound through liquids, solids and gas from fastest to slowest

Answer 6

solids > liquids > gases

Question 7

what is sound intensity

Answer 7

rate of energy movement through space

Question 8

what is the equation for sound intensity

Answer 8

I = f^2 x A^2

f = freq
A = amplitude

Question 9

what is the unit for sound intensity

Answer 9

decibels (dB)

Question 10

what is the equation for calculating decibels

Answer 10

dB = 10log10(I/Io)

Question 11

what is dB = 10log10(1000000) rearranged and solved

Answer 11

= 10log10(10^6)
= 6 x 10log10(10)
= 60log10(10)

dB = 60

Question 12

what is producing beats

Answer 12

when 2 sound waves of diff freq are heard together resulting in constructive and deconstructive interference causing sound to be alternatively soft and loud

Question 13

what is the relationship between the beat freq and the absolute value of diff in freq of the 2 waves producing the beats

Answer 13

equal

Question 14

what is the doppler effect

Answer 14

relative motion of observer and source of a wave is responsible for causing a shift in the freq of sound waves received by the observer

Question 15

what happens to the wavelength and freq if the distance between observer and source is decreasing

Answer 15

shift to shorter wavelength and higher freq

Question 16

what happens to the wavelength and freq if the distance between observer and source is increasing

Answer 16

shift to longer wavelengths and lower freq