i cant take it. there variables, and brackets, and.. OOH THE HORROR!!!
i just skipped it all, i couldnt possible take reading all that math.
the parts i did stick on(the demonstration slides), i found 1 problem, and one.. annoyance: problem; the one where you added the ground. if i moved the mouse fast enough i could get the ball INSIDE the wall, as though it were outside.
annoyance; the ball would only drop, i couldn't ''throw'' it. though im sure that was part of the programing that the ball would only be forced upon by gravity, nothing external except me positioning it.
anyways. looks like you put quite some work into it, so good job :)