Lesson 17 Key Concepts and Notes

1. Incident light can be reflected from and/or transmitted by a transparent block.

2. The direction of a light ray may change – be refracted – when it travels from one transparent material to another.

3. The extent that light is refracted depends on the angle of the incident ray.

4. The angle and change in the direction of light at it passes from one material into another depends on the composition of each material.

5. The angle and change in the direction of light as it is refracted depends on the direction the light is traveling when passing from one transparent material into another.

6. Why do we see an image in the window? A window is transparent so some light is reflected and some is transmitted.

7. As the angle of incidence increases, refraction increases, and transmittance decreases.

8. As the angle of incidence decreases, refraction decreases, and transmittance increases.

9. Refractive index: speed of light in a vacuum / speed of light in the transparent material * As speed decreases, refractive index increases – bends toward the normal

Material Refractive index Vacuum 1.0 Air 1.15 Pure Water 1.33 Glass 1.5-2.0 Diamonds 2.42

10. When light travels from a lower refractive index to a higher refractive index, it is bent towards the normal.

11. When light travels from a higher refractive index to a lower refractive index,, it is bent away from the normal.