WAVES

Page Contents
Overview
Waves Choice Work
Hanger Experiment
Wave Machine Demonstration
Color and Vision Simulation
Refraction Experiment
Light Behavior Experiment
How you See Color
Reflection Experiment
The Doppler Effect
Changing a Water Wave
Waves Notes
Quizlet Flashcards
Waves Prezi Slideshow
Waves Quiz





Overview
In the Waves Unit, students will be introduced to several new concepts involving the audible (hearing) and visible (seeing) world around them. Students will learn about general characteristics of waves as well as where waves are found in nature and used by humans.

Go to Waves Objectives





Waves Choice Work



Introduction to Choice Work
One of the aspects of Middle School growth that I feel is important is increased responsibility. Choice Work helps students take ownership of their learning.
During the Waves Choice Work project, students will be presented with different activities that will help them with their understanding of Waves. Many of the activities are required, while some of the activities are choices. Each choice assignment has a point value that can be earned for completing it successfully. At the end of the project, the points will be added up for a final grade.
Grade Scale:
A = 86 - 100 pts.
B = 71 - 85 pts.



Assignment Sheet and Calendar
Each student will receive two documents to help them get organized:



Worksheets
There are worksheets that go along with this project. Some are required, some are choices.
Required:


Choice:
What Are Waves - Online Worksheet




Waves Paragraph (10 pts)
Visit this site and scroll down to Electromagnetic versus Mechanical Waves to learn about the differences between electromagnetic and mechanical waves.
Use the information from the website to respond to the following BCR (brief constructed response.)

There are two types of waves; mechanical and electromagnetic. Describe each, giving at least two details for each. In your response, be sure to
• name each type of wave
• describe each type by giving at least two details for each type of wave
• give an example for each type of wave

Click here to answer the question online.



Explore Choices
  • Complete at least one of the following Explore Choice Experiments. You may work with a partner but you must turn in your own work.
  • Copy the Question and write your hypothesis for each experiment.

How Can You Change a Wave?
Question
To what extent does the amount of energy you put into a wave affect the size of a wave?

Hypothesis
I think... because....

Materials__
  • 1 rope or spring (a slinky would work)
  • 2 partners
    • two to move the rope or spring
    • one to read directions

Procedures

  1. Read All Procedures!
  2. Copy the Question and write down your hypothesis.
  3. Lay the spring on a smooth floor. Securely hold one end. Have a partner hold the other end .
  4. Have one partner move the end of the spring left and right about once per second to make a series of waves travel down the spring. The other partner should hold their end of the spring still. Observe the waves as they travel toward your partner. Draw a labeled diagram of what you see.
  5. Now move the end of the spring more often - about two times per second. Draw a new, labeled diagram to show any differences.
  6. Switch roles with your partner and repeat steps 2 and 3.

Conclusion
Answer the following questions about the experiment.
  1. What are the results of your experiment? (does the amount of energy you put into a wave affect the size of a wave?) Use details from the experiment to support your claim.
  2. Was your hypothesis correct?
  3. Was your data Qualitative or Quantitative? (click the link for a description of each) Explain what data shows this.
  4. What were the variables in this experiment? (click here for a review of some terms)
  • what is the Independent variable?
  • what is the Dependent variable?




Hanger Experiment

Question
To what extent does the type of medium affect how well a wave travels?

Hypothesis
I think...because...

Materials
  • metal coat hanger
  • 2 pc yarn (50 cm)
  • partner
  • quiet room

Procedures
  1. Read All Procedures!
  2. Copy the Question and write your hypothesis.
  3. Tie the end of each piece of yarn to the loop part of the coat hanger.
  4. Wrap the yarn around each index finger.
  5. Hang coat hanger down and have your partner tap the hanger with a pen or pencil. Record your observations.
    • What did you see?
    • What did you hear?
    • What did you feel?
  6. Repeat steps 1-3 with your fingers in your ears. (make sure you are leaning over a little and that the hanger is hanging freely and not touching you) Record your observations.

Conclusion
Answer the following questions about the experiment.
  1. What are the results of your experiment? (what is a better conductor of sound?) Was your hypothesis correct?
  2. Was your data Qualitative or Quantitative? (click the link for a description of each) Explain what data shows this.
  3. What were the variables in this experiment? (click here for a review of some terms)
  • what is the Dependent variable?
  • what are the Controlled variables? (there are more than one)



Online Resources
The science text has online resources to help you with this unit at home.



Other Web Resources

This slideshow, showing the parts of a wave, was created by a student.

Here is another slideshow that a student did.




Wave Machine Demonstration





Color and Vision SimulationThe following simulation will help you make a rainbow by combining red, blue, and green light. It will also help you see what happens when you use a filter on different colored light.Start by downloading this worksheet: Go to this site and choose Run Now to begin the simulation. Follow the directions on the worksheet.




Refraction Experiments

Magic Pencil
Materials:
• Pencil
• Water
• Clear Glass or Jar

Procedures:
1. Fill the glass or jar half way with water.
2. Place the pencil in the water.
3. Look at the pencil from the top.
4. Look at the pencil from the bottom
5. Look at the pencil from the sides.

Conclusion
  1. What happens when you look at the pencil through the top of the glass?
  2. What happens when you look at the pencil through the side of the glass?
  3. Draw a diagram of what you saw.

Floating Penny
Materials:
• Penny
• Water
• Clear glass or jar
• cup to pour with

Procedures:
1. Place the penny in the bottom of the glass.
2. Walk around and observe the penny from several angles – top, side, etc.
3. Have one person slowly pour water into the glass while others observe from different angles.
4. Repeat step three with a different person pouring and others observing from different angles.

Conclusion
  1. What do you see?
  2. How does the angle you observe from affect what you see?
  3. Draw a diagram of what you saw.

Explanation:
• What you observed in both experiments happens because light travels slower through different materials (such as water) than through air. As the light enters the glass of water it slows down and as it leaves the glass it speeds up again. If the light enters at an angle the pencil looks as though it is bent and the penny appears to float or disappear!.



Light Behavior Experiments
Light and Surfaces

Question
What happens to light when you shine it through different surfaces (water, milky water, and a solid cup)?

Hypothesis - make a hypothesis about the following:
  • I think that in the water the light will . . .
  • I think that in the milky water the light will . . .
  • I think that in the solid cup the light will . . .

Materials
  • clear container
  • water
  • flashlight
  • milk
  • solid cup
  • dark colored surface (notebook or binder)

Procedure
  1. First, stand the dark colored surface up on one side of the clear container containing water and shine the flashlight through the side of the cup so that the beam would hit the binder. Record your observations.
  2. Next, add a small amount of milk to the water and shine the flashlight through the side of the cup so that the beam would hit the binder. Record your observations.
  3. Now, stand the dark colored surface up on one side of the solid cup (you do not need to put any liquid in the solid cup) and shine the flashlight through the side of the cup so that the beam would hit the binder. Record your observations.

Conclusion
  1. When light passes through an object we say that it is transparent. Which of the cups was transparent?
  2. When only some light can pass through an object we say that it is translucent. Which of the cups was translucent?
  3. When all light is blocked we say the object is opaque. Which of the cups was opaque?





How you See Color





Reflection Experiment
Two Types of Reflection

Materials
• 1 piece of aluminum foil (15cm x 15cm)
• 1 flashlight

Procedures
1. Place the piece of aluminum foil on a flat table with the shiniest side facing up. Be careful to keep it smooth and unwrinkled!
2. Shine the flashlight at an angle on the surface of the foil and look up at the ceiling. What happens to the beam of light after it hits the surface?
3. Crumple the foil and then flatten it out.
4. Shine the flashlight at the surface of the crumpled foil and look back at the ceiling again. What happens to the beam of light now?

Conclusion
1. When light reflects with a perfect image of the original we say that it has a regular reflection. Which aluminum foil piece had a regular reflection?
2. If light is scattered when it hits a surface we say it has a diffuse reflection. Which aluminum foil piece had a diffuse reflection?
3. What are some examples of regular and diffuse reflections in your life?





The Doppler Effect


Doppler Effect Website



Changing a Water Wave
  • Is a water wave like a rope wave?
  • In this activity students investigate the similarities and differences between transverse waves that occur in different mediums.

Watch this short video showing a wave in a rope:


Individually, answer the following questions
  • Does a water wave have all of the same properties as a rope wave?
  • What are some differences between a rope wave and a water wave?
  • Can you change a water wave the same way you can change a rope wave?

Complete the following investigation with the other members of your group.

Materials
  • shallow tray that can hold water
  • pencil

Procedures
  1. Pour water into your tray until it just reaches the top edge without spilling over.
  2. Tap the surface of the water at one end of the tray once every second with the end of a pencil.
  3. Draw a diagram in your notebook to show the effects of this tapping on the surface of the water (remember that a diagram is a labeled drawing.)
  4. Now, tap the surface of the water twice every second. Try to tap with the same amount of energy. Draw a diagram to show the effects. Be sure to note any differences that may have occurred.
  5. Recall the names of the parts of a transverse wave:
    • rest position
    • crest
    • trough
    • wavelength
    • amplitude
  6. Did you see these parts in the water wave?
  7. What properties of the water wave did you change when you tapped the water more times? Describe the change. Be sure to use the above vocabulary.
  8. What would happen to the wave if you tapped the water three times per second? Why do you think this?
  9. How would you change the amplitude of your water wave? Explain what you would do and why you think it would work. Try it!
  10. Draw a diagram to represent your new wave.




Waves Notes - (click for fill in the blank PDF)


Waves Notes
Key Words
Definitions, facts, examples
Wave
  • A disturbance
  • Transfers energy from place to place
Medium
  • The material a wave travels through
  • Examples – water, air, solids
Mechanical wave
  • Waves that needs a medium to travel through
  • Made when an energy source causes a vibration
  • Two types – transverse and longitudinal
  • Ex. Water waves, sound waves, earthquake waves (seismic)
Electromagnetic wave
  • Waves that do not require a medium to travel
  • EM waves can travel through empty space
  • Ex – light, x-rays, radio waves
Vibration
  • A rapid, repeated, back and forth or up and down motion
Transverse Wave
  • Waves that move the medium at right angles
Crest
  • The highest point of a wave
Trough
  • The lowest point of a wave
Amplitude
  • The height of the wave
  • Measured from the center of the wave to the top or to the bottom
  • As the amplitude increases so does volume
Longitudinal Wave
  • Move the medium parallel to the direction the wave travels
  • Like a slinky
Compression
  • The place in a longitudinal wave where the particles are close together
Rarefaction
  • The place in a longitudinal wave where the particles are spread apart
Wavelength
  • The length of the wave
  • Measured from crest to crest or trough to trough
  • shorter wavelength equals higher frequency
Frequency
  • The number of waves that pass a point in a certain amount of time
  • as the frequency increases so does pitch
Hertz (Hz)
  • Unit used to measure frequency
  • Named for Heinrich Hertz
Reflection
  • When an object or wave hits a surface that it cannot pass through
  • Examples – mirror, bouncing ball, echo
  • two kinds - regular and diffuse
Regular reflection
  • reflection where the reflected image looks identical to what is being reflected
  • ex - a mirror
Diffuse reflection
  • when light reflects off of a surface at many different angles
  • ex - crumpled aluminum foil
Refraction
  • The change in speed and apparent bending of the beam of light as it passes from one medium into another
  • ex. - objects are not where they appear to be under water
Transparent
  • a surface through which all light can pass
  • ex – windshield
Translucent
  • a surface through which some light can pass
  • ex – waxed paper
Opaque
  • a surface through which light cannot pass
  • ex – brick wall
Decibel (dB)
  • unit used to measure volume







Use this companion Waves Study Guide




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Waves - Online flashcards and games
Do you have an iPhone or iPod Touch? Use the Touchcards app to study your Quizlet flash-cards. For the Waves unit use the code - 3846824 to access the virtual cards.




Waves Quiz
Click here to test your knowledge of the Waves Unit.