Algodoo

Only works with a low simulation speed.
It's just to demonstrate how you could calculate the acceleration for this forum thread.

Let it fall and change gravity and gravity direction to see that it works.

I'll try to improve it so that you can use it also with normal simulation speed.

I would apprechiate it if someone could make a better version!!
(Btw: the scripting was done with 2 big invisible circles. The rest is only for visualization)

- - - - -

x: acceleration in x-direction
y: acceleration in y-direction
res: the "real" acceleration (x and y united)