This applet graphs the orbit r, the magnitude of the velocity and the radial velocity of the reduced mass around its centre of mass, in a 2 body elliptical orbit scenario.[br][br][color=#ff0000]NOTE: [/color][br]It's better to download the .ggb file and run it with the app instead of the browser. It plays much more smoothly in the app.[br][br][b]Start by moving the reduced mass back to θ=0[sup]ο[/sup], by clicking the button on the top.[/b][br]To start the animation, check the box right under the top button.[br][br]The ratio of the masses can be changed using the m[sub]1[/sub] and m[sub]2[/sub] sliders.[br]In Graphics View 1, the quantities are graphed using a Cartesian plane, whereas in Graphics View 2 using polar coordinates.[br]You may also change the semi major axis a value, as well as the eccentricity, by adjusting the relative sliders.