Kepler's Second Law
- A Java Interactive Tutorial -Help File



Applet Operation
1. Adjust configuration.
2. Press Continue.
3. Press Start Sweeping.
4. Press Stop Sweeping before half revolution is completed. Look at the counters showing the time and the area swept during that time interval.
5. Press Start Sweeping again. The applet will run for the same time as in the previous sweep and it will stop automatically. Look at the counters showing the areas int he two sweeps.
6. Go to 4.for another sweep or go to 1. to load another configuration.

Viewing Controls
  • Pause/Continue buttons start and stop the simulation; The applet is initially paused.
  • Zoom In/Zoom Out buttons allow you to adjust the scale at which you view the simulation.
  • In addition you can enable/disable displays of the velocity, acceleration and the orbit, by pressing the appropriate check boxes.

    • Back to Applet Operation

Configuration Controls
By adjusting the sliders you can adjust the type of orbit simulated:

  • Star's Mass: adjusts the mass of the central star, measured in units of the solar mass.
  • Semimajor: adjusts the size of the orbit, measured in units of the size of the Earth's orbit.
  • Eccentricity: adjusts the shape of the orbit.
Note: adjusting any of these automatically resets the applet.
Back to Applet Operation

Sweeping Controls
These controls allow you to pick out areas to compare:
  • Start Sweeping: the line joining the planet and star will start sweeping out a colored wedge
  • Stop Sweeping: stops the sweeping process.
  • Erase Areas: causes all swept out areas to be forgotten.

Note: the values of the elapsed time, and area swept out for each wedge are displayed in a table at the lower left of the applet.
Back to Applet Operation

Last modified . Written by David McNamara and Gianfranco Vidali . Department of Physics, Syracuse University. This project was partially supported by a NSF- Curriculum Course Development Grant.