Waves Flashcards Preview

Application of Physics > Waves > Flashcards

Flashcards in Waves Deck (30):
1

How is sound created

Sound is just vibrations of particles. If the vibrations repeat periodically its called a periodic motion. Each repeat is a cycle

2

What is the frequency of a wave

The number of oscillations in 1 second

3

What is the time period of a wave

The time taken for 1 cycle

4

Frequency equation

F = 1/T

5

What is the Amplitude of a wave

The maximum displacement away from the equilibrium point

6

What is the phase of a wave

A measure of the position that a n oscillator is in its cycle

7

What is the phase difference of oscillators when they are in anti phase

180 degrees

8

For what condition will the phase difference between 2 waves satay the same?

They have the same frequency

9

What types of waves are sound waves?

Longitudinal waves

10

What is a wave?

An oscillation that travels through matter or space and transferring energy without transferring matter

11

How does pressure change with the compressions and refractions of a longitudinal wave?

Compressions - Increased pressure
Refractions - Decreased pressure

12

Wave Speed equation

Wave length x Frequency

13

What frequencies are the humans Ear sensitive to if the speed of sound in air is 340m/s

20Hz to 20kHz

14

How Does a Piezo-Electric Crystal microphone Create a voltage

Changes in pressure exert stress on the crystal which generates a small voltage

15

How does the human ear hear sound

Ear drum vibrates due to changes of pressure caused by waves. The hammer anvil and stirrup amplify the vibrations which are detected by the nerve endings in inner

16

How does a microphone hear sound

Pressure exert stress on piezoelectric crystal and generates a small voltage which is picked up by an electric signal.

17

Why does sound use a logarithmic scale

The range of sound intensity is several orders of magnitude

18

Sound Intensity equation

10log(I/I0)

19

what is sound intensity

Sound intensity is defined as the sound power per unit area

20

What is superposition

When 2 waves arrive at the same place at the same time the waves show a pattern of interference

21

What is a coherent wave

When a wave has constant frequency wavelength ad constant phase difference. They can have different amplitude

22

What conditions are needed for waves to have maximum constructive interference

Coherent and equal amplitude

23

What conditions are needed for maximum destructive interference

Out of phase by 180 degrees and equal amplitude

24

How do noise cancelling headphones work

Small microphone on outside of the head phones picks up ambient noise and destructively interferes with it cancelling it.

25

Phase difference equation

2pi Path difference/ wavelength

26

Stationary/ Standing wave

When travelling waves are reflected back and forth they are superimposed and form a stationary/standing wave

27

Look at separate notes for this lol

Got closed and open end waves and the harmonics stuff

28

End correction-what is it

The antinode extend beyond the open end of the pipe therefore the effective length of the pipe is longer

29

Transverse wave

Displacement of particles is perpendicular to the direction of propagation of the wave

30

L6 Starts now but first sort out the notes for the other one

Notes first K?