So you may know

1. OBJECTIVES:
 Explore the refraction property
of light.
 Determine what causes
bending of light.
 Relate refraction of light to real
life experiences.

4. REFRACTION
Is the BENDING of light as it
passes OBLIQUELY from
one medium to another of
different optical density.
Examples:
Air to water
Water to air
Water to glass

5. Why does LIGHT
bend?

6. Light bends because….
1. Of the change in MEDIUM.
Light bends as it moves
from one medium to
another like from air to
water.

7. Light bends because….
1. It changes speed as it
encounters a different
medium.

9. Light does not bend
when it enters the
medium perpendicularly,
however it slows down.

10. air glass
Incident
ray
1
Angle of incidence
Normal
line
2 Angle of refraction
Refracted
ray

11. What determines
the bending of light?

12. When light enters a medium of
greater optical density, it bends
towards the normal.

13. Normal line
incident
ray
i
less dense
denser
medium
r
i = angle of incidence
r = angle of refraction
i>r
refraction ray

14. Normal line
cident
y
i
less dense air
water
denser
medium
r
Light rays bend
angle of incidence towards the normal
angle of refraction air when the rays travel
glass
from a less dense
medium to a denser
refraction ray
medium
Light rays travel much
slower in a denser
medium

16. When light enters a medium of
lesser optical density, it bends away
from the normal.

17. Normal line
incident
ray
i
denser
medium
less dense
r
refraction ray
i = angle of incidence
r = angle of refraction
i<r

18. dent ray
i
denser air
medium water
less dense
r
Light raysray away from
refraction bend
angle of incidence the normal as it travels
= angle of refraction air from a denser medium to a
glass
less dense medium.
Light rays travel much
faster in a less dense
medium

19. LIGHT ENTERING WATER
FROM AIR

20. INDEX OF REFRACTION (n).
The ratio of the speed of light in
vacuum to the speed of light in the
material.
n Speed of light in vacuum = C
=
Speed of light in material v