Waves

Question 1

what are waves?

Answer 1

vibrations that transfer energy without net movement of matter

Question 2

wavelength

Answer 2

length of full cycle of a wave

Question 3

amplitude

Answer 3

displacement from rest

or maximum disturbance from undisturbed position

Question 4

frequency

Answer 4

number of full waves passing a fixed point per second

Question 5

unit of frequency

Answer 5

hertz - Hz

Question 6

formula for frequency and time period

Answer 6

f = 1/t

T=1/f

Question 7

formula for wave speed

Answer 7

frequency x wave length

Question 8

types of waves

Answer 8

tranverse

longitudinal

Question 9

tranverse wave

Answer 9

vibrations are perpendicular to direction of energy transfer

Question 10

longitudinal wave

Answer 10

vibrations are parallel to energy transfer

Question 11

examples of transverse wave

Answer 11

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

Question 12

examples of longitudinal wave

Answer 12

• sound
• P waves
• slinky spring pushed

Question 13

law of reflection

Answer 13

i=r

Question 14

how does reflection affect wave properties?

Answer 14

• does not change speed wavelength or frequency

Question 15

how does refraction affect wave properties?

Answer 15

• changes speed and direction

- does not change frequency as comes from outside source

Question 16

what is ultrasound?

Answer 16

high frequency sound wave >20,000 Hz

Question 17

uses of ultrasound

Answer 17

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

Question 18

what is doppler effect?

Answer 18

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