Standard: Describe how the behavior of light waves is manipulated causing reflection, refraction, diffraction and absorption. What am I learning today? How do light waves change when they hit different materials?

Wave Properties of Light

What happens when Light waves hit a surface? http://www.screencast.com/t/BcUW8HGzQfPI

Reflection occurs when a wave strikes an object and bounces off occurs with all types of waves obeys the Law of Reflection – the angle of incidence is equal to the angle of reflection

Law of Reflection

Refraction When a wave enters a new medium at an angle, one side of the wave changes speed before the other side, causing the wave to bend.

Refraction (cont.) amount of bending depends on the speed of light in both materials the greater the difference between the speeds of light in the two media, the more the light is bent if light slows down as it passes into the new medium, the light is bent towards the normal (an imaginary line drawn perpendicularly through the surface of the material) if light speeds up as it passes into the new medium, the light is bent away from the normal

Refraction (cont.) amount of refraction depends on the wavelength of the light red light is bent the least violet light is bent the most white light can be separated into colors by refraction in a prism

Diffraction bending of light around a barrier or through an opening occurs with all types of waves

Diffraction Website

Interference caused when light waves overlap each other constructive – interact to build up wave destructive – interact to reduce wave occurs in all types of waves white light can be separated into colors by diffraction and interference using a diffraction grating

Polarization Ordinary light has waves that vibrate in all directions A polarizing filters acts as though it has tiny slits in one direction Only some of the light (vibrating in the same way of the “slit”) can pass through a polarized filter Best example of a polarized filter is sunglasses Polarization Website

Reflection Example Complete the figure to the right to show the Law of Reflection.

Refraction Example Complete the path of a light ray as it goes through water, glass, and back into air

A prism is an example of Refraction

Prisms - ROYGBIV Label the colors of the spectrum you observed. What caused the white light to separate into colors?

Copy the organizer at the bottom of your notes sheet Copy the organizer at the bottom of your notes sheet. Match the Description to the behavior. Behavior (diffraction, reflection, absorption, refraction) Description of Wave Motion 1. Bounces off the surface at the same angle it hit with 2. Travels through material, but at an altered bent angle 3. Travels through the material until it encounters an obstacle or hole, which it bends around 4. Cannot travel all the way through the material