APS Excellence in Physics Education Award
November 2019

Science SPORE Prize
November 2011

The Open Source Physics Project is supported by NSF DUE-0442581.

## Computer Program Detail Page

Atwood Machine in Fluid Model
written by Wolfgang Christian and Jose José Goncalves
The Atwood Machine in a Fluid model shows two masses connected by strings and pulleys immersed in a water tank. Each mass is acted on by gravitational, buoyant, and drag forces. Users can change density of the left and right mass using input fields and can drag either mass to change the initial conditions.  Note that the floor of the tank produces a normal force that limits the motion.

If the water is removed the tank,  the model behaves like a traditional Atwood machine.  Adding water changes the dynamics in many ways.  Because the buoyant force varies as the mass is submerged, the system oscillates anharmonically about an equilibrium point that depends on the mass densities.

The Atwood Machine in Fluid model was created using the Easy Java Simulations (EJS) modeling tool.  It is distributed as a ready-to-run (compiled) Java archive.  Double clicking the ejs_mech_fluid_AtwoodMachineInFluid.jar file will run the program if Java is installed.

Please note that this resource requires at least version 1.5 of Java.
Subjects Levels Resource Types
Classical Mechanics
- General
- Newton's Second Law
= Force, Acceleration
= Interacting Objects
Fluid Mechanics
- Statics of Fluids
= Density and Buoyancy
Oscillations & Waves
- Oscillations
- High School
- Middle School
- Instructional Material
= Interactive Simulation
Intended Users Formats Ratings
- Learners
- Educators
- application/java
• Currently 5.0/5

Rated 5.0 stars by 1 person

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Access Rights:
Free access
This material is released under a GNU General Public License Version 3 license. Additional information is available.
Rights Holder:
Wolfgang Christian
Keywords:
Atwood machine, Buoyancy, equilibrium
Record Cloner:
Metadata instance created October 14, 2010 by Wolfgang Christian
Record Updated:
June 2, 2014 by Andreu Glasmann
Last Update
when Cataloged:
October 11, 2010
Other Collections:

### Modification

Author: Ahmedelshfie
Posted: August 23, 2011 at 9:05AM

I added a little modified for keep graphic together the applet.

can found at  http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2094.msg7860#msg7860

Post a new comment on this item

### NSES Content Standards

Con.B: Physical Science
• 9-12: Motions & Forces
ComPADRE is beta testing Citation Styles!

AIP Format
W. Christian and J. José Goncalves, Computer Program ATWOOD MACHINE IN FLUID MODEL, Version 1.0 (2010), WWW Document, (https://www.compadre.org/Repository/document/ServeFile.cfm?ID=10410&DocID=1886).
AJP/PRST-PER
W. Christian and J. José Goncalves, Computer Program ATWOOD MACHINE IN FLUID MODEL, Version 1.0 (2010), <https://www.compadre.org/Repository/document/ServeFile.cfm?ID=10410&DocID=1886>.
APA Format
Christian, W., & José Goncalves, J. (2010). Atwood Machine in Fluid Model (Version 1.0) [Computer software]. Retrieved June 14, 2021, from https://www.compadre.org/Repository/document/ServeFile.cfm?ID=10410&DocID=1886
Chicago Format
Christian, Wolfgang, and Jose José Goncalves. "Atwood Machine in Fluid Model." Version 1.0. https://www.compadre.org/Repository/document/ServeFile.cfm?ID=10410&DocID=1886 (accessed 14 June 2021).
MLA Format
Christian, Wolfgang, and Jose José Goncalves. Atwood Machine in Fluid Model. Vers. 1.0. Computer software. 2010. Java 1.5. 14 June 2021 <https://www.compadre.org/Repository/document/ServeFile.cfm?ID=10410&DocID=1886>.
BibTeX Export Format
@misc{ Author = "Wolfgang Christian and Jose José Goncalves", Title = {Atwood Machine in Fluid Model}, Month = {October}, Year = {2010} }
Refer Export Format

%A Wolfgang Christian
%A Jose José Goncalves
%T Atwood Machine in Fluid Model
%D October 11, 2010
%O 1.0
%O application/java

EndNote Export Format

%0 Computer Program
%A Christian, Wolfgang
%A José Goncalves, Jose
%D October 11, 2010
%T Atwood Machine in Fluid Model
%7 1.0
%8 October 11, 2010

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### Atwood Machine in Fluid Model:

Is Based On Easy Java Simulations Modeling and Authoring Tool

The Easy Java Simulations Modeling and Authoring Tool is needed to explore the computational model used in the Atwood Machine in Fluid Model.

relation by Wolfgang Christian

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