Chapter 7- Waves And Sound

Question 1

What type of wave is sound?

Answer 1

Longitudinal wave

Question 2

Transverse wave

Answer 2

Like people doing the wave in a stadium. Each person being a particle moving up and down (perpendicular)
Ex: electromagnetic waves

Question 3

Transverse wave and energy

Answer 3

Particles oscillating perpendicular to the direction of energy transfer

Question 4

Longitudinal waves and energy

Answer 4

Particles oscillate parallel to direction of energy transfer
Ex: sound waves

Question 5

Speed of wave

Answer 5

v = f(wavelength)

Question 6

Period of wave

Answer 6

T = 1/f

Question 7

Angular frequency

Answer 7

Used in simple harmonic motion in springs and pendula

w= 2(pi)f = 2(pi)/T

Question 8

Timbre

Answer 8

Quality of sound. Determined by natural frequency of the object

Question 9

Audible frequency

Answer 9

Between 20 and 20,000 Hz

Question 10

2 types of waves

Answer 10

1. Transverse

2. Longitudinal

Question 11

Speed of sound

Answer 11

Square root(B/density)

Question 12

Doppler equation

Answer 12

Detector / source

Question 13

Intensity

Answer 13

Pressure / Area

Question 14

Sound level

Answer 14

B = 10 log(I/I*)

I*- 1 x 10^-12

Question 15

Effects of dampening / attenuation

Answer 15

Same frequency (pitch), gradual loss of sound (smaller amplitude)

Question 16

Wavelength of standing wave

Answer 16

2L/n

n- number of half-wavelengths supported by the string

Question 17

Possible frequencies

Answer 17

f = nv/2L

Question 18

Fundamental frequency

Answer 18

First harmonic. Lowest frequency (longest wavelength) of a standing wave that can be supported in a given string.

Question 19

For strings attached at both ends how do you know which harmonic it is?

Answer 19

Number of antinodes

Question 20

For open pipes how can you tell which harmonic it is?

Answer 20

Number of nodes present

Question 21

Closed pipe equation for wavelength

Answer 21

4L/n

n- odd numbers only, quarter wavelengths

Question 22

Frequency of standing wave in a closed pipe

Answer 22

nv/4L

Question 23

Ultrasound machines calculate distance based on…

Answer 23

Travel time of the reflected sound

Question 24

Pitch

Answer 24

Related to frequency