Reflection and Refraction

Reflection and Refraction DonovenMiller, Amelia Spilde, Lukas Binau, Brandon Mock

Major Concepts • Reflection is the throwing back of an wave, such as light or sound by a surface that does not absorb it. The law of reflection is that the angle of incidence is equal to the angle of reflection. Refraction is the phenomena of waves traveling through an interface bedween one media to another becoming deflected and distorted.

Historical Perspective • The laws of refraction were described accurately by the Persian Scientist IbnSahl at the Baghdad court in 984, thugh it was rediscovered by Thomas Harriot in 1602.

Application • We see reflection in our mirrors around us and pools of liquids every day. We can see refraction through crystalline objects and glasses of water.

Think and Explain • 1. metals are a polished reflector • 2. If a pane of glass is considered to have two reflecting surfaces (front and back), then light is reflected twice. 92% is transmitted. • 3. the person will see the B card because the law of reflection says the angle of incidence is equal to the angle of reflection • 4. No, the reflected view reveals the object as seen from a lower angle • 5. so when you see the abulance in the rearveiw mirror the lettering looks normal so it can be read • 6. closer at 2 m/s as you and the image close distance by 2 metres • 7. Dry roads represent a diffuse surface and produce scattered reflection. Wet roads are smooth surfaces so they produce mirrored reflections. • 8. camera uses sound so it bounces from the mirror not the subject • 9. sonar travels about 1000 ft/s, the wall is 500 feet away • 10. when a sound is reflected some of it will be absorbed • 11. spear the fish below as the refraction of the water makes the fish look closer to the surface. with a laser you would aim directly at as it will have the same refraction. • 12. A rainbow viewed from an aeroplane form a complete circle because the earth does not come along the way of the aeroplane and rainbow. A rainbow is a three dimensional cone of dispersed light it appear as a complete circle. The shadow of the aeroplane appear with in the circle of the rainbow.

Reveiw • 1. all energy transmitted back, some energy transmitted back • 2. polished surface • 3. 4% • 4. line of reflection • 5. angle of incidence is equal to the angle of reflection • 6. same distance • 7. no • 8. yes as it affects every ray • 9. some waves travel at a smaller scale • 10. echo is reflected sound, reverberation is garble of an echo • 11. yes • 12. refraction is change in waves due to different medium • 13. travels differently in the new medium • 14. wave is perpendicular to the ray

Reveiw • 15. light travelling into water, sound travelling in air • 16. yes • 17. no • 18. yes • 19. shallower • 20. refraction as with sound it has a slight curve in wave front • 21. longer • 22. higher frequencies • 23. violent travels slower than red • 24. rain in opposite side as the sun • 25. has a medium cloer to ultraviolet frequencies • 26. when refraction becomes a reflection • 27. light in diamond is internally reflected several times • 28. pipe light from end to end

Background • Ancient Greek mathematician Euclid described the law of reflection in about 300 BCE. This states that light travels in straight lines and reflects from a surface at the same angle at which it hit it. Light is reflected in the same way that a ball would bounce off of a frictionless surface, and so Euclid claimed that light travels in rays that are discrete, like atoms, not continuous, like waves. This may mean that some of the objects in our visual field will always remain unilluminated, and therefore undetected. Unlike Ancient Greek philosopher Aristotle, Euclid thought that light is emitted in rays from the eye.

Hypothesis/question • How can we demostrate Reflection and Refraction of light? I hypothesize that we can demostrate reflection and refraction of light by simply using a flashlight, a mirror, and a piece of paper. • We will conduct the experiment by shining a light on the two different surfaces and seeing which one is reflective and which one isn't

Procedure & mats • 1. Flashlight (or any light source) • 2. Mirror • 3. Piece of paper • Step one, shine the light source on the mirror • Step two, shine the light on the paper • Analyse results Be attentive of wear you shine the light source and where you are reflecting it so you don't shine the light in someone's eyes

Data • You can see that on the mirror that the angle that the light is shown is the same angle that the light is reflected.

Conclusion • As you can see here the light source is bouncing off of the mirror at the same angle it hits on. And with the paper, most of the light is absorbed but if you look under the paper you can see a small portion of the light that shines through. • The reason for the light reflecting off of the mirro is due to the law of conservation of energy. This law states that all matter can not be created or destroyed, but can be transferred. The silver atoms in the mirror catch the light rays and reflect them back. As for the paper, this has no atoms that contain a reflective property, therefore the light is absorbed in the paper. • I believe that this was an accurate representation of Reflection due to the fact that the light source bounced off of the mirror at the same angle it was shown on

Reflection and Refraction