Transcript refraction power point

REFRACTION
THE BENDING OF LIGHT
WHAT TYPE OF WAVE IS LIGHT?
olight is a transverse wave
olight is an electromagnetic wave
that does NOT need a medium to
travel
Refraction: the
bending of light as it
passes from one
medium into another
of different optical
density
THE LAWS OF REFRACTION
1. Less to more
oBend toward
oAngle of refraction < angle of
incidence
oSlows down
THE LAWS OF REFRACTION
2. More to less
oBend away
oAngle of refraction >
angle of incidence
oSpeeds up
LAWS OF REFRACTION
3. No Bend
oOccurs when light
passes straight into
the medium
oAngle of incidence = 0
Willebrord Snellius (1580-1626)and Snell’s Law
1
1
2

2
sin( 1 )n1  sin( 2 )n2
INDEX OF REFRACTION
o Symbol n
o Indicates amount of bending
o Larger n = more bend
o Larger n= slower speed
n=1 for vacuum,
n=1.33 for water,
n=2.42 for diamond
n=1.5-1.9 for different types of glass
FINDING THE SPEED OF LIGHT
ospeed in vacuum = 3.00×108 m/s
(n=1.0)
on = speed of light vacuum/speed of
light medium