waves - refraction of waves Flashcards
what happens to light in water?
changes direction
when can waves change direction?
when changing speed from one medium to another
what happens when light passes from air into glass?
velocity of light decreases (slows down) which causes direction to change. they bend towards normal
what direction do waves bend when they slow down?
towards normal (90 degrees)
what happens when wave passes from glass back to air?
velocity increases (speeds up) causing change in direction, bend away from normal. makes image look like it has shifted position
which way does wave bend when sped up?
away from normal
when does refraction happen?
when any wave changes speed as it passes from 1 medium to another
what is an exception to refraction happening?
when the wave enters or leaves medium at right angles (normal) to the surface, they don’t change direction
what is wave front?
an imaginary line connecting all the same points in a set of waves which makes it easier to visualise lots of waves moving together
what happens to the wavefront when moving into glass?
it will start to slow down causing waves to get closer together making wavelength smaller so change in direction towards normal (refracting)
what happens to wavefront along normal?
whole wavelength slows down at same time so no change in direction
