waves Flashcards
what do waves do
waves transfer energy from one place to another
what are two types of waves
longitudinal
transverse
what are oscillations
up and down movement of waves
what type of wave is a sound wave
longitudinal
what type of wave is a ripple wave
transverse
what is the direction of energy transfer in transverse
oscillations perpendicular to the direction of energy transfer
energy transfer sideways
what is the direction of energy transfer in longitudinal
oscillations parallel to direction of energy transfer
what do longitudinal waves require that not all transverse waves do
a medium to travel through
what are compressions
in a l.wave, compressions are regions where air particles are very close together
what are rarefactions
in a l.wave, rarefactions are regions are where air particles are spread out
what is the only thing travelling
the wave not the medium
what is amplitude
furthest point the wave vibratees from its undisturbed position
what is wavelength
distance from a point on one wave to the equivalent point on the adjacent wave
how do you measure wavelength on a longitudinal wave
from one compression to another or one rarefaction to another
what is frequency
number of waves passing a point each second
what is frequency units
hertz- Hz
what is frequency equation (2 ways)
1/T or V/lambda
what is period and its equation
time in seconds for 1 wave to pass a point
period=1/f
what is wavespeed
2 ways
speed at which the wave moves through the medium or speed at which energy is transferred
what is wavespeed equation
v=fxwavelength
what is rarefaction of waves
waves can change direction when they change speed - moving from one medium to another
what happens when light passes from air into glass
the velocity of light decreases causing the direction of the waves to change
what happens when waves pass from the glass back to the air
their velocity increases causing the image to appear as shifted position
when can rarefaction happen
when any waves change speed as it passes from one medium to another
what is the exception to the rarefaction rule
if waves enter or leave the medium at right angles to the surface they do not change direction
