| Kepler's Second Law Applet IMPORTANT: This is a new window. To return to where you were please close this window. This applet demonstrates Kepler's second law of planetary motion which says that the imaginary line between a planet and the Sun sweeps out the same area of space in equal amounts of time everywhere along the planet's orbit. How Do I Use It? To run this simulation press the "start" button. You can pause the simulation at any time by pressing the "stop" button. Press "start" again to unpause it or press the "reset" button to make the input area reappear. The input area, which is inside the blue box, allows you to control the starting location and starting velocity of the planet just as you do in the Solar System applet. It also controls the length of the observational intervals. An observational interval is the amount of time for which one segment of the planet's orbit is measured. As you run the program, three readings in the upper right corner will tell you the time for which the simulation has been running, the number of intervals it has completed and the remaining amount of time for the current interval. Things to Try First run the applet with the default settings and stop it just as the planet is about to complete one orbit. Notice that each colored segment of the orbit is the same shape and size. Now reset the applet, change the planet's horizontal speed to 3 and run it again. This time the orbit will be elliptical instead of circular. Notice that here the planet moves faster when it is closer to the sun. Again stop the simulation just as the planet is about to complete one full orbit. Notice that each colored segment is a different shape yet the size of each segment, the area which it takes up, is still the same. |