Refraction

​ (a)   is the change in the direction of light.

• Refraction
• Reflection

Light travels at 

   different speeds in different materials.

• True.

• False.

• I don't know.

The light bends when it leaves the water. Your brain thinks ....

The light ​ (a)   when it leaves the water. Your brain thinks that light travels in ​ (b)   lines, so the pencil tip seems to be ​ (c)   the surface than it really is.

• bends
• straight
• nearer
• more far
• further
• unbends
• curves

All transparent materials, e.g. glass, plastic, water, diamond, etc. refract light.

• fastest

• Glass

• slower

• Air

• slowest

• Diamond

a

b

c

From glass to air: light speeds up

Light-along the normal, slows down

From air to glass: light slows down

From air to glass: light ​ (a)   and bends towards the normal due to entering a ​ (b)   dense medium. From glass to air: light ​ (c)   and bends away from the normal due to entering a ​ (d)   dense medium. When light enters along the normal, light ​ (e)   but does not bend / refract. They carry straight on.

• slows down
• more
• speeds up
• less

a

b

c

d

angle of incidence

transparent blick

normal

angle of refraction

c

d

e

f

b

a

incident ray

normal

angle of incidence

glass block

angle of refraction

refracted ray

Angle of incidence is smaller than the angle of refraction.

• True.

• False.

• I don't know.