Submitted by: Elyse Zimmer

Grade Levels: 9-12

In this lesson plan, adaptable for grades 9-12, students construct their own definitions for amplitude, tension, damping and frequency using the interactive simulation Wave on a String as a guide. As part of the investigation, they explore how waves behave with free, fixed and loose ends, relating their experiences to real world examples.

Students will:

  1. Investigate the properties of a transverse wave.
  2. Observe how waves behave when they have a loose, fixed or no end.



This lesson features an interactive simulation titled Wave on a String, developed by our award-winning partner PhET through the University of Colorado Boulder.  The simulation challenges students to create waves by wiggling a string, creating a pulse, or using an oscillator. Students explore how the frequency, amplitude, tension, and damping affect the motion of the wave. They also investigate how a wave behaves when it has a fixed end, loose end, or no end.

Photocopy a class set of the Waves on a String Investigation Lab and Waves on a String Exit Quiz.

Preview and play with the Wave on a String simulation to plan how you will adapt it to your students’ needs. If students will be working in small groups, review tips on Setting Cooperative Gaming Expectations.

Depending on your classroom routines and available technology, you may want to consider these grouping options:

  • 1:1 with students and devices
  • Two to three students sharing one device and swapping ideas and the device back and forth
  • Station model where small groups rotate through using the devices.
Build background knowledge or reinforce topics with these BrainPOP movies: Waves, Light, Sound, Electromagnetic Spectrum, and Radio.

Lesson Procedure:

  1. Distribute one slinky per pair of students. Ask them to make the slinky have three different shapes while having one student hold each end.  Then invite each pair to demonstrate the shape they were able to make. Discuss similarities and differences between the shapes students created.
  2. Distribute the Waves on a String Investigation Lab. Have students explore the Wave on a String simulation and make beginning observations (Part 1 of lab). Select two or three students to share their observations with the class. If possible, have students display their findings on the whiteboard for everyone to see.
  3. Introduce lab expectations. Then have students use the “manual” and “oscillate” functions in the simulation. Circulate while students are doing the investigation an ask the following guiding questions:
    • What are the characteristics of waves?
    • What is amplitude? Tension? Damping?
    • How does the amplitude affect the speed of the wave?
    • Are the waves in the simulation transverse or longitudinal?
  4. Lastly, distribute Waves on a String Exit Quiz to each student for them to complete individually.
Filed as:  9-12, Wave on a String