3.16- Plane Mirrors

For plane mirrors, the image is:

• The same size as the object
• The same distance as the object from the mirror
• Virtual (not real)
• Upright
• Laterally inverted

3.15- Angle of incidence and reflection

Recall that angle of incidence equals the angle of reflection

This shows that the light is reflected at the same angle

This shows where the angles are and the normal

3.14- Light waves

Light waves are transverse which can be reflected, refracted and diffracted.

Reflection: The change in direction of a light wave so that it returns into medium from which it originated.
Refraction: The bending of light when it passes between materials of different density.
Diffraction: Waves spreading into the shadow when they pass an edge.

3.12 and 3.13

3.12: Uses of electromagnetic radiations-
Radio Waves- Broadcasting and communications
Microwaves- Cooking and satellite transmissions
Infrared- Heaters and night vision equipment
Ultraviolet- Fluorescent lamps
X-rays - Observing the internal structure of objects and materials and medical applications
Gamma rays- sterilising food and medical equipment

3.13: Recall the detrimental effects of excessive exposure of the human body to electromagnetic waves-
Microwaves- internal heating of body tissue
Infra-red - skin burns
Ultraviolet- damage to surface cells and blindness
Gamma rays- cancer and mutation