Gravitational potential well

Roll ball bearings down the inclined ramp to launch them into orbits around a central potential. The cone-like surface is mathematically defined by the function Z = 1/R and is therefore the same as the gravitational potential of a planet or star. Use as a classroom demonstration to begin a discussion of motion in gravitational fields or the classical orbits of an electron in an atom. Teaching materials appropriate for all levels (orbits_description.tex and orbits_description.pdf) as well as the MATLAB code (orbits_3dprinting.m) used to generate this surface are available as well.