1. W4, W6 & W7 Notes

2. W4 Light is a type of electromagnetic radiation that always wants to travel in a straight line. The waves of light will travel in a straight line until they encounter matter and depending on the type of matter the light will either reflect, absorb, transmit or refract. Even after the light gets reflected, transmitted or refracted it will once again travel in a straight line. Look at the picture in the background, it shows light being reflected and refracted. In all instances the light is moving in a straight line.

3. W6 Lens and prisms can have a major impact on the path that light travels. A prism is an object that separates light into its different colors by bending the light, or refracting it. The object in the background is a prism. Drops of water or water vapor in the sky also acts as a prism at times, this is how rainbows are formed.

4. Lenses come in two major varieties, concave and convex. Concave lenses are thinner at the center than at the edges. Light waves that hit concave lenses spread out, or move farther away from each other.

5. Convex lenses are thicker at the center than at the edges. Light waves that pass through convex lenses will move closer together or converge. These are the most common types of lenses and are used for cameras, eye glasses and magnifying glasses.

6. W7 The amount of energy carried by a mechanical wave is related to the wave's amplitude. The greater the wave's amplitude, the more energy it transmits. Just remember the bigger an ocean wave the stronger it is. This rule does not apply to electromagnetic radiation waves.