Explore gravitational forces, especially as they apply tocircular and elliptical orbits.
1. With a big mass and a little one, simulate some orbits.What's necessary for there to be orbital motion? What kinds oforbital shapes can you make? What does the big mass do?
2. Try to make a circular orbit. Write down some observationsabout that process. Once you can do that pretty well, make anotherorbit at the same radius, but with a heavier planet how is thisdifferent (or not) from the previous orbit? What about circularorbits that are different distances from the big mass do they movefaster/slower? ...are their orbital periods (time for an orbit)shorter or longer?
3. How does an object move differently in the different parts ofan elliptical orbit?
4. How do different elliptical orbits compare in orbitalperiod?
5. What happens if you make a big mass \"orbit\" another big massthat looks different from what you've seen before? When does thatstart happening what sorts of masses do this?
