[pstricks] physics question

[Bob Tennent]

 >|what is the correct name for throughing a ball as seen in
 >|http://tug.org/PSTricks/main.cgi?file=Examples/Physics/physics
 >|(lower right picture. The direct translation of the german
 >|"schiefer Wurf" into "slate through" sounds a bit curious ...

I don't have any idea what the significance of "slate through" might be
but the diagram shows trajectories of a ball thrown at various angles.

Bob T.