Waves Interference Remote Lab 2 Interference
(This lesson is designed for a student working remotely .)
 This lab uses the Waves Interference simulation from PhET Interactive Simulations at University of
 Colorado Boulder, under the CC-BY 4.0 license.
 https://phet.colorado.edu/sims/html/wave-interference/latest/wave-interference_en.html
 Note about prior learning: Students should have completed Waves on a String Remote Lab and Waves
 Interference Remote Lab 1 (or Waves Intro Remote Lab ) or lessons with similar learning goals.
 Learning Goals: Students will be able to:
 A. Create an interference pattern with two sources, and determine the ways to change the pattern.
 B. Find points of constructive and destructive interference by eye and by using the detectors.
 C. Put up a barrier to see how the waves move through one or two slits. What sort of pattern do the
 slits create? How can you change this pattern?
 Develop your understanding: Open the Interference screen, then explore to make water waves with
 varying patterns.
 Explain your understanding:
1. Consider these three patterns of water waves:
 A B C
 a. Describe the similarities and differences of the three patterns of water waves.
 b. Experiment to make similar patterns, then explain how you can use the simulation to
 make each.
 c. Why do the directions say “similar patterns”?
 4/16/20 Loeblein https://phet.colorado.edu/en/contributions/view/5467 page 1
 Dianna Meera
 A little most
 interference
 interference NichterFerence
 → more circular
 All constant waves
 , A-& B have interference
 For C you only use one faucet . and you change the
 Frequency & amplitude to get
 All are waves with varying A to
 aMonts of interference
 
 2. Experiment to make waves of different interference patterns with water, sound, and light.
 Use your own words and captured images from the simulation to show you can meet
 learning goal A: “Create an interference pattern with two sources, and determine the ways to
 change the pattern.”
 3. Use the Water Level tool to understand what is happening in the
 water tank:
 a. Measure the dark and light areas of waves made with only one faucet. Insert a screen
 image to help explain your answer.
 b. Make waves using both faucets and measure the dark, light and fuzzy spots. Insert a
 screen image to help explain your answer.
 c. What do you think constructive and destructive interference means based on your
 measurements?
 d. Verify your understanding using your text or online references. (cite references)
 6767676
 4. Consider the light pattern on the right:
 a. Describe where the points of constructive and destructive
 interference are in the image on the right.
 b. Create a similar wave pattern and use the detectors to find points of
 constructive and destructive interference.
 c. Explain how you made the waves and used the detector. Insert an
 image of the entire screen for evidence.
 4/16/20 Loeblein https://phet.colorado.edu/en/contributions/view/5467 page 2
 you
 can create different patterns by either increasing
 ordecreasing the frequency & amplified
 constructive- troughforests meet destructive -crest meets trough
 to result in higher aammpplhttuyddee results in smaller amputee
 
 5. These three patterns were made with sound waves by varying only one thing.
 .
 A B C
 a. What do you think was varied?
 b. Test your idea by making similar patterns.
 c. Is there more than one way to make these three patterns by varying only one thing? Test
 your ideas and provide evidence for support.
 d. Try to make similar patterns with light. Describe your observations and ideas.
 6. Summarize key ideas that you want to remember about the relationships of interference
 patterns of water, sound and light waves.
 4/16/20 Loeblein https://phet.colorado.edu/en/contributions/view/5467 page 3
 Frequency
 You can
 vary both frequency & amplitude
 decreasing amplitude makes the image bleary
 interference leads to waves to superimpose
 on eachother which creates a resulting
 wave