Bellwork: This week we will learn about the Law of Reflection. What is the difference between a Law and a Theory? compare the wavelengths of visible light to infrared and ultraviolet light A sound wave traveled through the air and entered the water in a swimming pool. How was the wave affected by this change? How are light waves (part of the EM spectrum) different from sound waves?

Interactions of Light EQ: How do waves interact with matter? Obj: Describe how waves interact with matter Describe how waves change direction http://studyjams.scholastic.com/studyjams/jams/science/energy-light-sound/light-absorb-reflect-refract.htm

How do light waves interact with matter? Absorbed - The transfer of energy to matter The amount absorbed depends on the material. Darker Colors absorb more light waves A material that absorbs all wavelengths of visible light will appear black. In contrast, a material that reflects all wavelengths will appear white.

Absorption The apple absorbs all wavelengths except red. Yellow Green Red Blue Orange Violet The apple absorbs all wavelengths except red. The apple reflects mostly red. Therefore, it looks like red.

2. Transmitted Transmission is the passage of light through an object The object absorbs only a small amount of the energy Transparent objects (glass) transmit all Translucent objects transmits it and scatters it Opaque objects - no light waves are transmitted

Which Solo cup is Transparent? Translucent? Opaque?

3. Reflected The bouncing of a wave off of a surface Sound waves = echo Light waves bounce off a mirror

What is the Law of Reflection? When a wave is reflected, the angle of incidence is equal to the angle of reflection.

Law of reflection Discuss with your partners what you think this law means in your own words Use the mirror and light or the Tennis ball and the wall to see if the law holds true

Label the type of light interaction shown in each of the blanks below: 2. 1. 3. 4.

4. Refracted Refraction - the bending of a wave caused by a change in its speed as it moves from one medium to another.

Refraction Lab Write-up – On notebook paper: parts of your lab report: Title: Purpose: Read objectives and paraphrase to write up a purpose Materials: list the materials you will use in the lab Procedure: you can just write see lab Analysis and Conclusions: Number and answer questions 2-7 as you do the lab. Make sure to use complete enough sentences that I can tell what the question was.

Bellwork: Why is a control group important in an experiment? The dark, dull pavement that covers Katie's driveway gets very hot in the daytime. Why does the pavement get hot?     The sound waves traveled through the air and struck a wall. What happened to the sound waves when they struck the solid wall? Which type of reproduction is used in the process below. Which type of cell division created the cells that combined in this example? .

What causes light waves to change direction? Reflection Refraction Scattering

How do waves change direction Reflection Refraction scattering Description Example Illustration Other info

scattering When light strikes matter and changes direction. Allows you to see objects that aren’t directly in path of light Ex – flashlight lights up whole room when pointed at a wall. Shorter wavelengths scatter more. (blue scatters more than red) The sky is blue due to scattering. Particles in air scatter blue light more than other colors, so it seems to be coming from every direction in the sky. http://www.physics-chemistry-interactive-flash-animation.com/optics_interactive/light_source_primary_secondary_scattering.htm

Bellwork Name a translucent material. How are the frequency, wavelength, and energy of electromagnetic waves related? You are spending your day off at the beach surfing. Which property of a wave might be most important to you? Vocab writing: An alarm clock is placed in a sealed glass container without any air. Describe what you will observe when the alarm clock goes off. Use as many vocab words of in your description as you can.

Instructional conversation An alarm clock is placed in a sealed glass container without any air. Describe what you will observe when the alarm clock goes off. Turn to your partner and describe what you might observe. Use as many of the the following words in your description as you can. Vocab points Light wave Vacuum (empty space) Electromagnetic wave Medium Sound wave Mechanical wave transparent

INSTRUCTIONAL CONVERSATION Directions: Describe the type of wave topic listed to your partner. Tally a point each time your partner uses a vocabulary word. Total up the points for each vocab word used in their description. VOCABULARY Waves Disturbance Crest Trough Wavelength Frequency Energy Matter Media Transverse

Exit: Give examples of situations in which you see an object because (a) light is reflected, (b) light is refracted, (c) and light is scattered. For each situation, explain the path of light and any change in direction of the light.

Waves reflection VOCABULARY Angle of incidence Angle of reflection Law of reflection interaction matter