EJS Digital Library for Physics 200

Week 1: Simple Explicit Models

The first two week's objective will be to become familiar with the EJS modeling environment and to compile and run simple examples that demonstrate basic syntax.  Readings and in-class examples will cover the following:

• Importance of computers in physics
• The nature of computer simulation
• The EJS modeling and authoring environment

Homework (Due Friday Jan 27, 2012)

• Use EJS to plot the gravitational potential starting at the Sun's surface, passing through the center of Earth, and continuing outward until the distance from Sun is twice the radius of Earth orbit.  (Assume the potential is zero at infinity.)   Set the scale so that Earth appears near the center of the plot.
• Add a slider to zoom in on the potential function at the location of the Earth.

Turn in your model (via email).  The completed model should contain an HTML documentation page with a screenshot of the potential energy graph and a discussion of the significance (importance) of the Earth's gravitational field for the Earth and Sun potential for travel to other planets in the solar system.  Describe the programming difficulties that needed to be solved to create the plot and to show the potential dip when passing through Earth.