2. Allow students minutes to decide on their strategy to demonstrate the properties described.

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Sabina Lambert
5 years ago
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1 ROLE PLAY Materials: Task card for each team Procedure: 1. Divide the class into 3 groups to role play as a team a model of the light indicated on their card. (Include more students in the Unpolarized Light group as they will need several students to represent different wavelengths in different planes.) 2. Allow students minutes to decide on their strategy to demonstrate the properties described. 3. Assess the students on applying information learned in previous activities regarding the card description. (Example: a wavelength has crests and troughs) 4. Have students demonstrate their model for the class. Task Observed Yes No Unpolarized Light Polarized Light Different wavelengths for different colors of light; light traveling in different directions to represent different planes Different wavelengths for different colors of light; Light traveling in one plane Laser Light The same wavelength for the same color of light; Light traveling in one plane

2 Task Cards UNPOLARIZED LIGHT The electromagnetic waves vibrate in a variety of directions and in different planes. Light is made of different colors, and thus, different wavelengths. POLARIZED LIGHT The electromagnetic waves vibrate in one plane. Light is made of different colors, and thus, different wavelengths. LASER LIGHT The electromagnet waves vibrate in one plane. Laser light is made of one wavelength.

3 Absorb, Reflect or Transmit? Imagine that electrons are connected to atoms by springs. The electrons of the atoms will vibrate at a natural frequency. The frequencies differ for elements. Light particles also vibrate at a natural frequency. As light waves strike matter (made of atoms), the light will be absorbed, transmitted or reflected. Light waves that have the same natural frequency as atoms making up an object will be absorbed, and they will set the electrons of the atoms into vibration at their natural frequency. The energy will then be changed to heat energy. Light waves that do not have the same natural frequency will be transmitted or reflected. Light is transmitted if the object is transparent and reflected if it is opaque. What determines the following: Light is absorbed? reflected? transmitted? The electrons that have the same frequency as the light are set into motion. This is an example of resonance--one object causes another object to vibrate because they have the same natural frequency.

4 Building a Spectroscope Materials: (per student) Toilet tissue tube Diffraction grating Index card Electrical tape Ruler Markers Scissors Pencil Packing tape Procedure: 1. Trace the end of the toilet tissue tube onto the index card and cut out the circle. 2. Cut a small square (~1.5 cm 2 ) or a small circle (~1.5 cm diameter) in the center of your circle made from the index card. 3. Place a piece of diffraction grating (slightly larger than the hole) over the hole. Tape the edges of the diffraction grating down with electrical tape. Do not tape over the center of the diffraction grating (you will look through this opening). 4. Place the cut-out circle on one end of the tube and secure it with electrical tape. 5. Cover the opposite end of the tube with electrical tape allowing for an opening in the center, measuring 1 mm and 1 cm long. This slit will allow the light into the tube. 6. Cover other holes or spaces with electrical tape to prevent light pollution. 7. Decorate your tube with a spectrum or other colorful images. 8. Cover the entire tube with packing tape for added protection. 9. Point the spectroscope at the lights and look through the end with diffraction grating. You should see a spectrum. 10. Look at different lights with your spectroscope to compare the patterns you observe. How does it work? Diffraction grating is a film with thousands of fine, parallel slits. As light travels to the film, it runs into obstacles and bends to pass through the grooves. The light spreads around the edges of the obstacle or defracts. As the light bends, it separates into its different wavelengths and a spectrum is visible. Activity adapted from Suzy Dunnum, Tahoka Hr. High School, 8 th grade

5 Building a KaLeidOscOPe Materials: 2 Dixie cups Polarizing film Transparent tape (glossy) Scissors Procedure: 1. Cut the bottom from two Dixie cups. 2. Tape a piece of polarizing film onto the end of each cup. 3. Tape over the polarizing film on each cup with numerous pieces of tape in random patterns (more tape and a more random placement makes for a better kaleidoscope!). 4. Slip one cup inside the other cup and look to the light through the open end as you twist the cups. Observe the spectacular display of color! How does it work? Activity adapted from Suzy Dunnum, Tahoka Hr. High School, 8 th grade

A Wave of Cooperation

A Wave of Cooperation The students will peer teach in cooperative learning groups some basic topics regarding waves. Materials: Student sheets Note sheets Procedure: 1. Place students into home teams of