We continue our study of the numerical solution of ordinary differential equations by studying dynamical models that appear in upper-division physics classes. Although some of these models have simple analytic solutions, many do not. Studying and analyzing the EJS implementation of a models is, in fact, similar to doing a laboratory experiment and often provides us with a novel perspective on the behavior of the system.
This week's models will also introduce EJS 3D drawing components.
Free Fall 3D simulates the same physics as the Free Fall model but with a 3D View of the model's data. The ball falls with constant acceleration g=-9.8 m/s2 in the z direction. Click-dragging on the ball changes its height but leaves its velocity unchanged. The reset button
stops the animation and sets the initial conditions to y=1.8 and vy=0. See the Free Fall model for a description of this model is implemented in Ejs.
The following dynamical models will be discussed in class.
Additional models may be be posted for self-study.
The Free Fall 3D Model was created by Wolfgang Christian using the Easy Java Simulations (EJS) version 4.1 authoring and modeling tool. You can examine and modify a compiled EJS model if you run the model (double click on the model's jar file), right-click within a plot, and select "Open Ejs Model" from the pop-up menu. You must, of course, have EJS installed on your computer.
Information about Ejs is available at: <http://www.um.es/fem/Ejs/> and in the OSP comPADRE collection <http://www.compadre.org/OSP/>.