Education Prize Logo
Science SPORE Prize
November 2011

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

Computer Program Detail Page

Item Picture
Graphs and Tracks Model
written by Wolfgang Christian and Mario Belloni
The Graphs and Tracks Model allows instructors to create custom models of a ball rolling on a track with a variable shape. This EJS model was inspired by the Graphs and Tracks program by David Trowbridge. Instructors set the heights of the track segments and the model displays the motion of the ball. Optional displays, including position and velocity graphs, energy graphs, and data tables, can be added depending on the learning goals for the activity. Documents can be added to the model to provide student instructions or activities.  The customized simulation is then saved as a new jar file that can be redistributed.

The Graphs and Tracks 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 jar file will run the program if Java is installed.

Please note that this resource requires at least version 1.6 of Java (JRE).
3 supplemental documents are available
1 source code document is available
Subjects Levels Resource Types
Classical Mechanics
- Applications of Newton's Laws
- Motion in One Dimension
= Acceleration
- Motion in Two Dimensions
= 2D Acceleration
= 2D Velocity
- Newton's Second Law
= Force, Acceleration
- Lower Undergraduate
- High School
- Instructional Material
= Activity
= Interactive Simulation
Intended Users Formats Ratings
- Learners
- Educators
- Professional/Practitioners
- application/java
  • Currently 5.0/5

Rated 5.0 stars by 2 people

Want to rate this material?
Login here!

Access Rights:
Free access
This material is released under a GNU General Public License Version 3 license.
Rights Holder:
Wolfgang Christian
force, motion, simulation
Record Cloner:
Metadata instance created May 30, 2012 by Wolfgang Christian
Record Updated:
October 15, 2014 by Wolfgang Christian
Last Update
when Cataloged:
May 30, 2012
Other Collections:

Issues w/ x(t) and a(t) graphs

Author: plulai
Posted: November 18, 2015 at 12:15PM

I have found 2 bug issues.  
I had students create a ramp with a height of 0 at the 0cm x-axis and a height of 10 units at the 20 cm x-axis position.  Students set xo=20 and vo=0.
For this setup, the x(t) graph shows the original position as 0 even though the graph and the [xo=0] box show the original position as 0.  The x(t) graph then shows all following positions as negative values.  

The acceleration graphs are really strange for most graphs. An object rolling on a straight ramp produces a(t) graphs that look like a stairwell.

Thanks for your work on the simulation and for sharing it with the community.
Have a good one.

» reply

Re: Issues w/ x(t) and a(t) graphs

Author: Bruce, ComPADRE Dir
Posted: Nov 18, 2015 at 6:26PM

Hi Paul,

For the first issue, the graph that's being shown is not x(t), but displacement as a function of time:
x(t) - x(0). That's why in your example, where the object starts at the maximum x, the graph is everywhere negative. It's possible to create an x(t) graph rather than, or in addition to, the displacement graph.

On the acceleration graph, the acceleration is a constant (g sin(theta)) in each interval between each node on the ramp. This gives the steps. Even if the ramp is nearly straight at one of the nodes, there will still be steps in the a(t) graph. This can look a little strange in several cases.

One sure way to get a constant acceleration is to change the number of movable nodes to 2, but setting N = 2 in the customization window. Give it a slope and you'll get constant acceleration.

» reply


Author: Paul Camp
Posted: July 18, 2012 at 12:45PM
Source: The PSRC collection

This modernized version of Graphs and Tracks has some nice features but excluding an acceleration graph seems like a strange omission.

» reply

Re: Acceleration?

Author: Bruce, ComPADRE Dir
Posted: Jul 30, 2012 at 11:04PM

Thanks, Paul. The model has been updated with the option for an acceleration graph.

» reply

Post a new comment on this item

AAAS Benchmark Alignments (2008 Version)

4. The Physical Setting

4E. Energy Transformations
  • 6-8: 4E/M4. Energy appears in different forms and can be transformed within a system. Motion energy is associated with the speed of an object. Thermal energy is associated with the temperature of an object. Gravitational energy is associated with the height of an object above a reference point. Elastic energy is associated with the stretching or compressing of an elastic object. Chemical energy is associated with the composition of a substance. Electrical energy is associated with an electric current in a circuit. Light energy is associated with the frequency of electromagnetic waves.
  • 9-12: 4E/H1. Although the various forms of energy appear very different, each can be measured in a way that makes it possible to keep track of how much of one form is converted into another. Whenever the amount of energy in one place diminishes, the amount in other places or forms increases by the same amount.
4F. Motion
  • 3-5: 4F/E1a. Changes in speed or direction of motion are caused by forces.
  • 3-5: 4F/E1bc. The greater the force is, the greater the change in motion will be. The more massive an object is, the less effect a given force will have.

NSES Content Standards

Con.B: Physical Science
  • 5-8: Motion & Forces
  • 9-12: Conservation of Energy & Increase in Disorder
ComPADRE is beta testing Citation Styles!

Record Link
AIP Format
W. Christian and M. Belloni, Computer Program GRAPHS AND TRACKS MODEL, Version 1.0 (2012), WWW Document, (
W. Christian and M. Belloni, Computer Program GRAPHS AND TRACKS MODEL, Version 1.0 (2012), <>.
APA Format
Christian, W., & Belloni, M. (2012). Graphs and Tracks Model (Version 1.0) [Computer software]. Retrieved January 17, 2017, from
Chicago Format
Christian, Wolfgang, and Mario Belloni. "Graphs and Tracks Model." Version 1.0. (accessed 17 January 2017).
MLA Format
Christian, Wolfgang, and Mario Belloni. Graphs and Tracks Model. Vers. 1.0. Computer software. 2012. Java (JRE) 1.6. 17 Jan. 2017 <>.
BibTeX Export Format
@misc{ Author = "Wolfgang Christian and Mario Belloni", Title = {Graphs and Tracks Model}, Month = {May}, Year = {2012} }
Refer Export Format

%A Wolfgang Christian
%A Mario Belloni
%T Graphs and Tracks Model
%D May 30, 2012
%O 1.0
%O application/java

EndNote Export Format

%0 Computer Program
%A Christian, Wolfgang
%A Belloni, Mario
%D May 30, 2012
%T Graphs and Tracks Model
%7 1.0
%8 May 30, 2012

Disclaimer: ComPADRE offers citation styles as a guide only. We cannot offer interpretations about citations as this is an automated procedure. Please refer to the style manuals in the Citation Source Information area for clarifications.

Citation Source Information

The AIP Style presented is based on information from the AIP Style Manual.

The APA Style presented is based on information from APA Electronic References.

The Chicago Style presented is based on information from Examples of Chicago-Style Documentation.

The MLA Style presented is based on information from the MLA FAQ.

This resource and its subdocuments is stored in 12 shared folders.

You must login to access shared folders.

Graphs and Tracks 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 Graphs and Tracks Model.

relation by Wolfgang Christian

Know of another related resource? Login to relate this resource to it.
Save to my folders



Related Materials

Similar Materials

Featured By

Open Source Physics
May 30 - Jun 30, 2020

Jun 22 - Aug 13, 2012

The OSP Network:
Open Source Physics - Tracker - EJS Modeling
Physlet Physics
Physlet Quantum Physics