3What is a lens, and how does it change the path of light? Challenge Question:What is a lens, and how does it change the path of light?Take time now to write down your Initial Ideas!
4Evidence/Data:The sun emits energy that makes up the electromagnetic spectrum.Visible light makes up only a small part of this broad spectrum.
5While otherparts of theelectromagneticspectrumcan be detected,the human eye canonly detect visiblelight.
6Light travels in straight lines away from its source ... Laseruntil it is re-directed by an object….
7Light travels in straight lines away from its source ... LaserUntil it is re-directed by an object…..this is called RELFECTION
8We see things because they reflect light into our eyes: Homework
9Reflection of Light: Reflection from a mirror: Mirror Normal Incident rayReflected rayAngle of incidenceAngle of reflectionMirror
10Angle of incidence = Angle of reflection The Law of ReflectionAngle of incidence = Angle of reflectionIn other words, light gets reflected from a surface at ____ _____ angle it hits it.The same !!!
11We can demonstrate this by splitting white light with a prism. White light is not a single color. It is made up of a mixture of the seven colors of the rainbow.We can demonstrate this by splitting white light with a prism.This is how rainbows are formed.Sunlight is “split up” by raindrops.
12Adding colorsWhite light can be split up to make separate colors. These colors can be added together again.The primary colors of light are red, blue and green:Adding blue and red makes magenta (purple)Adding blue and green makes cyan (light blue)Adding red and green makes yellowAdding all three makes white again
13Only red light is reflected Seeing colorThe color an object appears depends on the colors of light it reflects.For example, a red book only reflects red light:HomeworkWhitelightOnly red light is reflected
14A white hat would reflect all seven colors: A pair of purple trousers would reflect purple light (and red and blue, as purple is made up of red and blue):Purple lightA white hat would reflect all seven colors:Whitelight
15Refraction of Light:Light can also be refracted. Refraction is the bending of light as it passes from one transparent material (such as air) into another transparent material (such as water).The ruler looks bent because the light is refracted as it passes from the air into the water.
16A lens is a curved transparent object that refracts light. Light raysLensThere are different types of lenses.A convex (or converging) lens is thicker in the middle than at its edges. It bends light toward its center.A concave (or diverging) lens is thinner in the middle than at its edges. It bends light away from its center.
18Lenses are used in many different applications, including…. ConvexlensesCombination of convex & concave lenses
19Analysis Questions:What is the difference between the reflection of light and the refraction of light?What are the different types of lenses, and where can they be found in everyday life?3. When light is refracted it is bent as it passes from one transparent material to another. Why does the light bend?