Waves & Sound

Question 1

Waves in which the direction of particle oscillation is perpendicular to the movement (propagation) of the wave is termed ?

Answer 1

Transverse waves

Question 2

Waves in which particles oscillate parallel to the propagation of the wave is termed ?

Answer 2

Longitudinal waves

*Air molecules oscillate through cycles of compression & rarefaction (decompression)

Question 3

The max magnitude of displacement in a wave is called what ? (from the equilibrium position)

Answer 3

Amplitude

Question 4

What is the principle of superposition & what does it encompass ?

Answer 4

When waves interact w/ each other, the displacement of the resultant wave @ any point is the sum of displacements of the 2 interacting waves
C interference: waves in sync
D interference: waves not in sync

Question 5

The quality of sound, which is determined by the natural frequency of an object, is known as ?

Answer 5

Timbre

Question 6

A decrease in amplitude of a wave caused by a nonconservative force is known as ?

Answer 6

Damping/Attenuation

Question 7

Our perception of the frequency of sound is called the what ?

Answer 7

Pitch
*20-20,00 Hz: normal range of human hearing
Below 20 Hz: infrasonic
Above 20,000 Hz: ultrasonic

Question 8

The difference between the actual frequency of a sound & its perceived frequency when the source of the sound & the sound’s detector are moving relative each other is known as ?

Answer 8

Doppler effect: f’ = f*(v+-vD)/(v-+vs)

vs>vd = f'>f
vs>vd = f'

Question 9

The way in which we perceive the intensity of sound is termed ?

Answer 9

Loudness or volume

Question 10

What is used to determine the flow of blood within the body by detecting the frequency shift that is associated w/ movement toward or away from the receiver ?

Answer 10

Doppler ultrasound

Question 11

How is sound produced & how is the speed of sound calculated ?

Answer 11

Longitudinal wave that moves by the movement of particles (cannot move through a vacuum)
Speed of sound: v= sqrt B (bulk modulus)/p(density)

Question 12

The bulk modulus is a measure of what ?

Answer 12

A measure of the mediums’ resistance to compression

Question 13

What is the relationship of the speed of sound in different mediums ?

Answer 13

Solids>liquids>gases

Question 14

How is the intensity of sound & sound level measured ?

Answer 14

I = Power/Area (W/m^2)
B = 10*log*I/Io (dB)
I = intensity of sound wave
Io = threshold of hearing (1E-12 W/m^2)

BONUS:
New Sound Level: Bf = Bi + 10logIf/Ii

Question 15

The effect of a build up of wave fronts due to an object having a greater speed than sound will create what ?

Answer 15

Shock wave

Question 16

The point in a standing wave with no fluctuation in displacement, & the point w/ max fluc. are known as what respectively?

Answer 16

Nodes & antinodes