Hi prof,
i try to add slider for have diffrent positions to satellite so will be have also diffrent velocity, for example when satellite be near from earth velocity will be more fast and when be far
velocity will be more slowly, what i need to do that add slider for me control space between satellite and earth to can shown the diffrent velocity when change positions of satellite.
In case that i talk is this satellite motion at [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2244.0]http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2244.0[/url]
Also i need to know how when i change position the satellite trace change automatic too.

thanks,