Earth  and Moon 
This is a simulation of a reduced two-body problem.
I have used data for the Earth and the Moon just to make it more attractive . The rotation is simulated using animated gifs. However, in slow machines, this can unnecesarily waste some computer resources. Hence, if the simulation behaves strangely, substitute the animated gifs for the static ones you will find in the data directory.
The difficult part is certainly to set up initial conditions so that the elliptical orbit has a period that approximates the real one of the Moon around the Earth. As an exercise for your students, delete the initialConditions initialization page and ask your students to reproduce it!

Author : Francisco Esquembre 

/htdocs/ntnujava/ejsuser/2/users/examples/EarthAndMoon_pkg/EarthAndMoon.propertiesFull screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
Download EJS jar file(1444.6kB):double click downloaded file to run it. (7 times by 6 users) , Download EJS source (5 times by 4 users) View EJS source