Phet wave on a string answers

EDS 1021 Week 4 Interactive Assignment

Wave on a String

Objective: To observe and manipulate the various properties of waves using an interactive simulation of a wave on a string.

Background: Review the topic Nature of Waves in Chapter 6 of The Sciences

Instructions:

1. It is recommended that you PRINT a hard copy of this entire document, so that the experiment instructions, data tables, and questions may be easily referred to and completed while running the simulation.

2. Download the Wave On a String Answer Sheet from the course website. Enter your data values and question answers into the answer sheet file. Put your NAME on the answer sheet where indicated. Save your completed answer sheet on your computer.

3. SUBMIT ONLY the completed answer sheet, by uploading your file to the digital drop box for the assignment.

Introduction to the Simulation

1. After reviewing the background information for this assignment, go to the website for the interactive simulation

“Wave on a String” at http://phet.colorado.edu/en/simulation/wave - on - a - string . Click the play button on the icon image to run the simulation.

2. Get oriented to the simulation by exploring and manipulating all of the possible variables and options:

MODE: Manual, Oscillate, Pulse. In Oscillate and Pulse modes, you can pause/play and step, and also change other settings regarding the wave characteristics:

AMPLITUDE: 0 to 1.25 cm

FREQUENCY: 0 to 3.00 Hz

DAMPING: None to Lots

TENSION: Low to High

END: Fixed, Loose, or No End

RULERS: display (box checked) or not (box unchecked). When displayed, you will see two rulers, one horizontal and one vertical.

TIMER: display (box checked) or not (box unchecked); start/pause/reset

REFERENCE LINE: dashed line that can be used as a reference for amplitude measurements

Note: The rulers, timer, and reference line can all be dragged around as needed. In addition to the reference line, there is another dashed line parallel to the undisturbed string that is fixed (not moveable).

While getting oriented with the simulation, think about how the different wave properties discussed in chapter 6 are being illustrated in the simulation, and how changing things in the simulation affects the wave properties.

Once you are oriented to how the simulation works, conduct the following four (4) short experiments. As you conduct the experiments and collect data, fill in the data tables and answer the questions at the end of this document.

Experiment 1: Manipulating a Wave on a String

1. Set Up: For this experiment, set the MODE to manual, the DAMPING to None, and the TENSION to high.

2. Procedure:

a. Set the End to NO End. Wiggle the wrench up and down at varying speeds and over various distance ranges. Observe the differences in the properties of the waves produced for varying wiggle action. After wiggling for several seconds, let go of the wrench and observe what happens.

b. Click “Restart”. Change the End to Loose End. Wiggle the wrench as in part a. Observe the differences in the properties of the waves produced with the Loose End compared to No End. After wiggling for a bit, let go of the wrench, set the speed to “slow motion”, and observe what happens.

c. Click “Restart” and set the speed back to “Normal”. Change the End to Fixed End. Wiggle the wrench as in part a. Observe the differences in the properties of the waves produced with the Fixed End compared to No End and the Loose End. After wiggling for a bit, let go of the wrench, set the speed to “slow motion”, and observe what happens.

d. Answer the six (6) questions for Experiment 1 on the Questions page.

Experiment 2: Measuring Wavelength

1. Set Up: Click “Restart”. Set the MODE to Oscillate, set the AMPLITUDE to 0.50 cm, Set the FREQUENCY to 1.00 Hz, set the DAMPING to None, set the TENSION to high, set the END to No End, and display the RULERS. For this experiment, we will be changing the FREQUENCY setting.

2. Procedure

a. After observing the generated waves with the oscillation wheel turning, hit the PAUSE button.

b. Measure the wavelength in centimeters (cm), by using the horizontal ruler to measure the horizontal distance between consecutive wave crests (highest part of the wave) or between consecutive wave troughs (lowest part of the wave). In data table 2, fill in the wav