Waves Flashcards Preview

BMAT: Physics > Waves > Flashcards

Flashcards in Waves Deck (18):
1

what are waves?

vibrations that transfer energy without net movement of matter

2

wavelength

length of full cycle of a wave

3

amplitude

displacement from rest
or maximum disturbance from undisturbed position

4

frequency

number of full waves passing a fixed point per second

5

unit of frequency

hertz - Hz

6

formula for frequency and time period

f = 1/t
T=1/f

7

formula for wave speed

frequency x wave length

8

types of waves

tranverse
longitudinal

9

tranverse wave

vibrations are perpendicular to direction of energy transfer

10

longitudinal wave

vibrations are parallel to energy transfer

11

examples of transverse wave

- light
- EM waves
- S waves
- slinky spring up and down

12

examples of longitudinal wave

- sound
- P waves
- slinky spring pushed

13

law of reflection

i=r

14

how does reflection affect wave properties?

- does not change speed wavelength or frequency

15

how does refraction affect wave properties?

- changes speed and direction
- does not change frequency as comes from outside source

16

what is ultrasound?

high frequency sound wave >20,000 Hz

17

uses of ultrasound

- sonar: ships use ultrasound to locate fish
- medical imagine: pregnant women
- removing kidney stones: vibrations break up stone
- animals: locating prey

18

what is doppler effect?

change in frequency and wavelength
- source moves towards source - high frequency, short wavelength - high pitch
- source moves away from source - low frequency - long wavelength - low pitch