5.2 understanding refraction of light

 *     i ; incident angle

*  r ; refracted angle

when light travel from a less dense to a denser medium , the ray is refracted toward the normal at point of incidence
when light travel from more dense medium to less dense medium , the ray is refracted away from the normal at point of incidence

snell's law states that sin i and sin r is constant

PHENOMENON

1. shallow swimming pools
 a swimming pool appering to be shallower than it really is , this is due to the lights rays from the bottom of the pool being refracted away from the normal as they  enter the air . when the light rays reach the eye , they appear to come from I which is higher up . so , the pool appears to be shallow .

2. a fish-eye view
a fish or a diver can see objects above the water surface , but the objects on the shore would appear to be up in the air at different positions . due to refraction of light , a fish sees the image of an object at a position that differs from its true positions

3. bent objects in water
the pencil appearing to be bent at the air-water boundary . the light rays from the end of the pencil are refracted at the air-water boundary and bend away from the normal . the image of the pencil under the water appears to be higher than it really is . thu, the pencil appears bent at the surface .

SOURCES ;
http://www.google.com.my/imghp?hl=en&tab=wi
FOCUS SPM Form 4 * 5 Physics (page 230 and 235)