2. Line Ray Beam the paths along which light energy travels a bundle of light rays

3. Three ways in which rays are grouped in light beams : parallel converging diverging

4. These are what happen when light encounters any substance, they can be: A A’ the light is reflected if it strikes the surface of a substance and bounces off the light is absorbed if it strikes the surface of a substance and just disappears the light is transmitted if the light goes through the material and leaves in the same direction the light is refracted if the light is bended as it travels through the substance

5. Our eyes able to see an object only when the light rays coming from the object enter our eyes. Objects Luminous objects are light sources that emit light and we are able to see them directly Examples :.... Non-luminous objects are seen only because they reflect light from a source Examples :....

6. diffused reflectionregular reflection reflection the rays are reflected in many different directions the rays are reflected in parallel directions rough surface smooth surface

7. The Laws of Reflection 1.The angle of incidence is equal to the angle of reflection. 2.The incidence ray, the reflected ray and the normal at the point of incidence all lie on the same plane. reflected rayincidence ray normal at the point of incidence plane mirror angle of incidenceangle of reflection ir

8. O object i image M plane mirror observer

9. The position and characteristics of the image formed in a plane mirror can be summarized as follows : 1.It is virtual (it cannot be formed on a screen). 2.It is upright. 3.It has the same size as the object. 4.It is the same distance behind the mirror as the object is in front. 5.It is laterally inverted (reversed left-to-right).

10. S2/Gr.8/HO/Physics/Light/2009.10 rif_kee1011@yahoo.com