The Question. What are the 4 types of interactions that waves can have when they encounter an object?

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Mabel Robbins
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1 The Question What are the 4 types of interactions that waves can have when they encounter an object?

2 Waves, Wave fronts and Rays Wave Front: Crests of the waves. Rays: Lines that are perpendicular to the wave fronts and show the direction of wave travel.

3 Waves, Wave fronts and Rays How do we diagram how waves travels (on paper)? Think of a light ray as a little laser beam. Laser beams travel in straight lines.

4 When Waves Encounter Objects Core Defintions Absorption: The wave or energy is transferred to the object (typically as heat). Example: A black shirt in the sun. Reflection: Waves bounce off the object and go in a new direction. Example: Light and a mirror and piece of paper. Refraction: Waves bend when they go from one object to another. Example: Light in glass and water. Diffraction: Waves bend around corners and objects. Example: Sound around a corner.

5 Absorption The energy of the wave is given to the object that absorbed the wave. Black shirt in the sun. Think nastyburger sitting under the heat lamp at McDs. Where does the heat from the lamp go?

6 Reflection Reflection: The process of light rays bouncing off a surface. There are two types of reflection: Specular reflection: Light rays strikes a shiny surface (like a mirror) and they create single reflected rays.

7 Reflection A surface that is dull or uneven creates diffuse reflection. Diffuse Reflection: Light rays strikes a rough surface (like a piece of paper) and many reflected rays are created.

8 Law of reflection Normal Line: A line that is perpendicular to the mirror and starts from where the light ray hits the mirror. Otherwise known as the air hockey rule: Incident angle equals the reflected angle.

9 Diffraction Waves can bend when they come to an opening or corner that is the same size as the wavelength. Think sound around a corner.

$Refraction Light will bend when it enters a different type of material. This bending is called refraction.$

10 Refraction Light will bend when it enters a different type of material. This bending is called refraction. Index of refraction is the property that measures how much a material is able to bend light. The bigger the number, the more light bends.

11 3 Types of Optical (Light) Devices Mirror: A surface that reflects light. Lens: An optical device that bends light. Prism: A optical device (typically made of glass) that has flat polished surfaces that can both bend and reflect light. The shape of a prism is a triangle.

12 Lenses Focal Point: The point that the light rays focus to after passing through the lens.

13 Lens Converging Lens: A lens that causes light rays to bend towards each other after passing through the lens.

14 Lens Diverging Lens: A lens that causes light rays to bend away from each other after passing through the lens.

15 The Answer What are the 4 types of interactions that waves can have when they encounter an object? 1. Absorption 2. Reflection 3. Refraction 4. Diffraction

16 The Question What is the Doppler Effect?

17 The Doppler effect JPvGML9A0 When Humans hear a sound wave they interpret the frequency of the wave as pitch. When an object making sound is not moving, the frequency (pitch) will be the same to all listeners. The frequency (pitch) will not change.

18 The Doppler effect g9f5pn5tli 5KaeCZ_AaY

19 The Doppler effect Doppler effect: A shift in frequency (and wavelength) caused by an objects motion. When the object making the sound is moving, the frequency (pitch) will not be the same to all listeners. The frequency (pitch) will change. This is true of all waves, not just sound waves. Light (how we know how far stars are from the earth), sound, water You hear the Doppler effect when you hear a police siren coming toward you, then going away from you.

21 The Answers What is the Doppler Effect? A shift in frequency that is caused by a moving object.

Reflections. I feel pretty, oh so pretty

Reflections. I feel pretty, oh so pretty Reflections I feel pretty, oh so pretty Objectives By the end of the lesson, you should be able to: Draw an accurate reflective angle Determine the focal length of a spherical mirror Light Review Light