Satellites and Kepler's Laws

[Miriverite]

Homework Statement

http://mp.pearsoncmg.com/probhtml/ActivePhysics/pt1a/Media/CircularMotion/SatellitesOrbit/Sim1.html
This applet shows satellites orbiting a central body from various starting distances. The mass of the central body is much greater than the masses of the satellites. You should think of this applet as data obtained in an experiment (e.g., a set of videos made by compiling data of observations of satellites).

Determine the orbital period Tp of the purple (innermost) satellite when it has an initial speed of 2.0. (For this problem, the units are chosen for convenience and may be ignored for the first few parts of the problem.) Note that simply watching one orbit and seeing how long it takes will not give you three significant figures. Try to think of a technique that will.

2. The attempt at a solution
I can't really attempt this problem since my computer doesn't seem as if it wants to display the applet properly. I don't really need help on solving the question itself; I just need someone to tell me what the applet entails and if anything appears in those black text boxes (are they numerical data? I can't see them). Please help; this is due tomorrow and I have found no method of getting this applet to display properly.

 

[Chewy0087]

The text boxes merely show the speed which happens to be adjustable;

Red - 4.0
White - 4.0
Purple - 2.0