Superlesson
Project 3-3
Geometry
Chapter 3, Angles and Parallel Lines
Light interacts with different surfaces in different ways. Some substances do not allow light to pass through them. Some of these, such as mirrors, reflect the light. Other substances do let light through, but bend the light rays. You can see this phenomenon, called refraction, if you put an object in water. Below, we will examine both light reflection and light refraction.
Part C, Making Connections
1. Go to the Light and Optic site to see a basic discussion of light reflection.
a. According to this article, what is the law of reflection, or Fresnel's Law?
b. Sketch Figure 1.c. Suppose that the measure of angle i is 51°. Write the measures of all the other angles in your sketch above.
d. Label points on each of the line segments in your sketch using letters of your choice. Label the point where the light hits the surface point O.
e. Give all pairs of complementary angles in your sketch.
f. Give all linear pairs in your sketch.
2. Now, go to the Reflections Web site to see a discussion of reflections from curved surfaces.
a. Suppose you stood in front of a convex mirror. What would your image look like?
b. Suppose you stood very close to a concave mirror. What would your image look like?c. When you stand far away from a concave mirror, why is your image flipped upside down?
d. What is the focus of a concave mirror?
3. Next, we'll look at the phenomenon called refraction. Read the article at the Light, Reflection, and Refraction Web site.
a. According to this article, what is refraction?
b. What do you think causes refraction?
4. Look at the Total internal reflection Web site. Read the article and study the picture at the very end.
a. What is happening to the beam of light?
b. Sketch this picture. Be sure to include the original beam of light, the reflected beam, the refracted beam and the surface of the water.
c. Let's suppose that the acute angle between the original beam and the water surface measures 46°, and the acute angle between the refracted beam and the water surface measures 7°. Find the measures of all the other angles in your sketch, and write them in your sketch.