Waves and Radiation Light

Learning Outcomes Light travels in straight lines. Reflection of light. Convex and concave lenses. Applications of light.

Lesson 1 Learn how to draw a normal. 2. Prove the law of reflection.

Light Visible light is part of the electromagnetic spectrum. It only travels in straight lines.

Reflection Why does the moon “glow”, when it is simply a piece of rock? When you see objects, it is because light is being reflected off of the surfaces of that object. The moon glows because it reflects light from the sun.

Drawing a Normal Copy! A normal is a line drawn at right angles to a surface. All angles that are used in studying light are taken “from the normal”. x Ray of light 1. Where does the light strike the surface? 2. At this point, draw a dotted line at right angles to the surface.

Experiment Aim To study the reflection of light.

Method Plane Mirror Angle of Incidence i r Sheet of Paper Ray box with single slit Angle of Reflection Normal line Draw a straight line along which the ray of light will travel. 2. Draw in the normal. 3. Measure the angle of incidence, i. 4. Switch on the ray box. 5. Measure the angle of reflection, r. 6. Repeat for different angles of incidence.

Angle of Reflection (º) Results Angle of Incidence (º) Angle of Reflection (º) 1 2 3 4 5

Conclusion – The Law of Reflection Copy! When light is reflected, the angle of incidence is equal to the angle of reflection. Plane Mirror Angle of Incidence i r Angle of Reflection Normal line

2002

2006