1. Mr. Chapman Science 8

2.  The change in direction of light, called refraction, occurs because light travels at different speeds through different materials.  As light passes from air to water, it slows down and changes direction.  To see why this is the case, open your textbook to page 113 and examine the row of skaters on the left-hand side.

3.  When light travels through a substance, it will change direction based on the properties of that substance, because the light will change speeds.  For example, light travels at different speeds through air and water. The index of refraction is a measure of how much the speed of light is reduced in each substance.

5.  http://www.physics.uoguelph.ca/applets/Intro_ physics/refraction/LightRefract.html http://www.physics.uoguelph.ca/applets/Intro_ physics/refraction/LightRefract.html

7.  Glass is transparent and easy to shape. Mirrors are made by applying a reflective coating to glass.  We can also use glass without a reflective coating in order to refract light instead of reflect it. This allows us to focus light.

9. 1. When would it be easier to for a bear to catch a fish: as the fish jumps into the air, or as it swims? Explain your reasoning in terms of how light travels through air and through water. 2. We looked at the analogy of skaters to explain how light refracts. Can you think of another analogy to explain refraction to someone?

10.  Open your textbook to page 119 and examine the pictures of the different people using the property of refraction. What are the people trying to accomplish in each picture?

11.  When you experimented with mirrors, you found that the shape of the mirror had an effect on the image.  The image reflected by a concave mirror was smaller and upside down when the object was far away.  The image reflected by a convex mirror was larger and right side up.  This makes mirrors very useful.

12.  A lens is a piece of transparent material (glass, plastic) with at least one curved surface.  A convex lens curves outward. It is thicker in the middle than on the edges.  A concave lens curves inward. Concave are thinner in the middle than on the edges.

13.  In your notes, title a page with: Types of Lenses, and then sketch each type of lens found on page 121 into your notebook. Label each type of lens as well.  Complete questions 1, 2 and 4 on page 123!