### Notes:

The Wavelength Concept Builder is an adjustable-size file that displays nicely on smart phones, on tablets such as the iPad, on Chromebooks, and on laptops and desktops. The size of the Concept Builder can be scaled to fit the device that it is displayed on. The compatibility with smart phones, iPads, other tablets, and Chromebooks make it a perfect tool for use in a 1:1 classroom.

### Teaching Ideas and Suggestions:

Many Physics courses will begin the topic of waves with a discussion of wave properties such as wavelength, frequency, period, amplitude and speed. This concept provides students with practice recognizing the number of waves displayed in a pattern and using such information to determine the wavelength. This Concept Builder is intended for use near the early to middle stages of a learning cycle on wave properties and mathematical relations.

This Concept Builder was intended as an in-class activity. After some brief discussion of the definition and meaning of wavelength, accompanied by some guided practice with several examples, allow students to put the principles into practice by the completion of the exercise. The Concept Builder includes three activities. Teachers using the Concept Builder with their classes should preview the activity (or view the Questions in the separate file) in order to judge which activities would be most appropriate for their students. There is no redundancy from one activity to another activity. That is, all the questions in the third activity are unique to that activity.  Our summary of the three activities is as follows:

• Wave Anatomy: 4 questions on recognizing crests, troughs, compressions and rarefactions.
• Counting Waves: 4 questions on counting the number of waves in a given pattern.
• Determining Wavelength (most difficult): 4 questions on the length-wavelength relationship for various wave patterns.

In order to complete an activity, a student must correctly analyze each question in that activity. If a student's analysis is incorrect, then the student will have to correctly analyze the same or very similar question twice in order to successfully complete the activity. This approach provides the student extra practice on questions for which they exhibited difficulty. As a student progresses through an activity, a system of stars and other indicators are used to indicate progress on the level. A star is an indicator of correctly analyzing the question. Once a star is earned, that question is removed from the que of questions to be analyzed. Each situation is color-coded with either a yellow or a red box. A red box indicates that the student has incorrectly analyzed the question and will have to correctly analyze it twice before earning a star. A yellow box is an indicator that the question must be correctly analyzed one time in order to earn a star. Once every question in an activity has been analyzed, the student earns a trophy which is displayed on the Main Menu. This system of stars and trophies allows a teacher to easily check-off student progress or offer credit for completing assigned activities.

The most valuable (and most overlooked) aspect of this Concept Builder is the Help Me! feature. Each question group is accompanied by a Help page that discusses the specifics of the question. This Help feature transforms the activity from a question-answering activity into a concept-building activity. The student who takes the time to use the Help pages can be transformed from a guesser to a learner and from an unsure student to a confident student. The "meat and potatoes" of the Help pages are in the sections titled "How to Think About This Situation:" Students need to be encouraged by teachers to use the Help Me! button and to read this section of the page. A student that takes time to reflect upon how they are answering the question and how an expert would think about the situation can transform their naivete into expertise.

### Related Resources

There are a few resources at The Physics Classroom website that serve as very complementary supports for the Wavelength Concept Builder. These include:

• Minds On Physics Internet Modules:
The Minds On Physics Internet Modules include a collection of interactive questioning modules that help learners assess their understanding of physics concepts and solidify those understandings by answering questions that require higher-order thinking. Assignments WM1, WM2, AND WM3 of the Wave Motion module provide great complements to this Concept Builder. They are best used in the middle to later stages of the learning cycle. Visit the Minds On Physics Internet Modules.

Users may find that the App version of Minds On Physics works best on their devices. The App Version can be found at the Minds On Physics the App section of our website. The Wave Motion module can be found on Part 5 of the six-part App series. Visit Minds On Physics the App.

• Curriculum/Practice: There is at least one Concept Development worksheet at the Curriculum Corner will be very useful in assisting students in cultivating their understanding, most notably ...

Describing Waves

Visit the Curriculum Corner - Wave Basics

Additional resources and ideas for incorporating this Wavelength Concept Builder into an instructional unit on Vibrations and Waves can be found at the Teacher Toolkits section of The Physics Classroom website.  Visit Teacher Toolkits.