Waves transport energy and momentum without transporting matter. If an approaching storm creates a water wave, this water wave can travel far from where it was created; but only the wave not the water has traveled. If you speak the vibration of your vocal cords create sound and this sound wave is transmitted through the air to your friend’s ear, which detects the sound (luckily your vocal cords stayed with you). Light also behaves like a wave. It is an electromagnetic wave, as are radio waves, microwaves, or X-rays. The wave speed is determined by the characteristics of the medium through which the waves travel. Not all waves need a medium to travel through. Electromagnetic waves (like light) can travel through vacuum, and they do so with the speed of light. Interference is caused when waves superposition. If the waves are in phase their amplitudes add (constructive interference) and when they are out of phase a wave crest meets a trough and they cancel each other out (destructive interference). A reflected wave can superposition with itself and under special conditions a standing wave can be created. Standing waves are the basis of many musical instruments.

The wave nature of light is important when slits, apertures or obstacles are in the same order of magnitude as the wavelength. Effects that can be understood using the wave nature of light are interference and diffraction. For example many colors like those on soap bubbles or hummingbird wings are not created by pigments but the result of interference of light.

So far we have discussed the properties of waves using simple models like a wave on a string or a Slinky, circular water waves and sinusoidal waves. To appreciate how many different phenomena can be understood by adopting the wave description for sound, light, or other waves we will brainstorm and research some effects or applications that are based on wave properties.

Learning Objectives

Course Objective:

• increase relevance of studying physics to everyday life

Primary Learning Objectives

• When communicating numerical information the learner will consistently use scientific notation, metric prefixes and appropriate (SI) units.

• By the end of this course the learner will be more confident in interpreting information from graphs, diagrams, tables and figures and use this information in answering conceptual or numerical questions.

Content Specific Learning Objectives

• After this lesson the learner will describe the conditions under which the superposition of waves will produce constructive or destructive interference. The learner will apply the principle of superposition to explain interference.

  Standing waves (on strings or in tubes) are a special case of interference.

Find one phenomena that can be explained with the wave model of sound, electromagnetic waves, water waves or other waves.

We will use a Google document titled “Waves in Everyday Life” to brainstorm those ideas. To get you started with ideas I listed already the first possible topics.

Find at least three resources (best something that is available on the internet, so everybody in class can access it) that help explain those phenomena. You may find three resources for one topic (not necessarily “yours”) or one each for three topics. Resources can be more than articles for example you might find helpful simulations or online lectures. List those in the Google document for the relevant topic together with a short comment about its content.

Visit the document to see what wave phenomena we all came up with. For three of the topics think what questions you have about this topic, what you would like to know more about. Use the “insert comment” in Google documents to add your question to the topic.

Select one of the phenomena listed and write a short report (1-2 pages) about it. If possible try to address any of the questions asked for this topic.

Here is a checklist what your report should address:

• Your introductory paragraph describes the phenomena or application to an audience of college students, not necessarily having your major.

  (Everybody in class should be able to understand what you wrote.)

• The phenomena can be explained using a wave model.

  (For example how to form images with lenses could be explained using the ray model of light, so this is not applicable as an example for the wave nature of light.

• You give the explanation in your own words (you are the author) and the text is not copied from a textbook or a source on the web. The explanation should connect the phenomenon to basic principles we discussed in class (e.g. constructive/destructive interference, diffraction etc.) and demonstrate correct conceptual understanding

• Correct terminology is used and the notation should follow those used in class or in Walker 3^rd ed. Physics and any additional quantities need to be introduced

• Your report should include a figure illustrating the concept. Figures need to be referenced

• Sources used (books, articles, internet…) are referenced.

Resource for theory:

http://www.stmary.ws/physics/amsco_review_and_glencoe/chapter04.pdf

Resource for physics in everyday life:

www.flyingcircusofphysics.com

How the assignment is graded:

- 5 points for adding one topic to the Google document.

- 15 points for contributing three resources that help explain the listed wave phenomena in the Google document

- 10 points for asking questions about three of the topics

- 55 points for writing a summary report about one topic (a detailed rubric follows below)

- up to 6 bonus points for addressing the questions asked

For you to know what you should aim for and be successful refer to the following

scoring rubric: rubric_wavephenomena.pdf

I will evaluate your report using this rubric and suggest you use it for self-check while working on the assignment.

QM Rubric standards and comments:

Standard III.1: “The types of assessments selected measure the stated learning objectives and are consistent with course activities and resources.”

• brainstorming and researching everyday phenomena related to waves in a Google document will increase the perceived relevance of physics to everyday life.

• creating a written report about literature research for one wave phenomena is an application of communicating scientific information.

• explaining a phenomenon provides evidence for assessing the student’s reasoning skills.

• selecting or creating figures practices the use of visuals for communicating scientific information.

Standard III.2: “The grading policy is transparent and easy to understand.”

• providing up front a the point weight for each part of the assignment as well as a scoring rubric for the report (the final portion of the assignment) not only makes the grading policy transparent it also allows for self-check and helps students gauge what quality works looks like.

Standard V.1: “The learning activities promote the achievement of stated objectives and learning outcomes.”

• starting the assignment with a team brainstorming exercise and team resource sharing, then collectively identifying questions to ask when preparing the report will support the individual student when preparing the report of their chosen topic.

Standard V.2: “Learning activities foster instructor-student, content-student, and if appropriate to this course student-student interaction.”

• interaction occurs asynchronous via a shared Google document to which all students contribute and are required to ask questions that stimulate deeper interaction with the content. Instructor-student interaction will occur via comments in the shared document.

Standard VI.1: “The tools and media support the learning objectives of the course and are integrated with texts and lesson assignments”

• communicating in a Google document allows for online collaboration, peer review

• after having received an introduction to the content topic and worked through some simulation exercises to develop conceptual understanding the student is finally required to demonstrate their understanding by presenting information in logical order, with correct terminology to an audience of peer students.

Standard VI.2: “The tools and media enhance student interactivity and guide the student to become a more active learner.”

• researching applications of newly learned content with the freedom to choose the area of interest (e.g. musical instruments, technological applications, colors in the animal world etc.) and co-authoring a document actively engage the student with the learning process; starting this assignment as collaborative effort enhances student interactivity.

Standard VI.3, VI.4, VI.6:

• accessing a Google document only requires a free Google account and a web browser.

Accessibility and Usability

• asynchronous interaction allows each student to spent as much time as needed for the task and allows for individual scheduling.

• modifications for students with disabilities can be implemented as with any other access to web content.

   

Ethical Considerations

• the 4-step process of brainstorming, collecting resources, asking questions and finally creating a report using these resources makes it less likely that a student plagiarizes and downloads a ready-made report.

• working through the initial steps collaboratively will give each students better opportunity to do well on the assignment.

• students can within the boundary of the assignment select a topic of their personal interest.