1.0 link Rainbow Dash Network http://rainbowdash.net/ aaaaaaaaaa (aaaaaaaaa) http://rainbowdash.net/aaaaaaaaa http://rainbowdash.net/notice/151776 @<span class="vcard"><a href="http://rainbowdash.net/user/1022" class="url"><span class="fn nickname">starlightbolt</span></a></span> I don't know if it's a two-step process. I would use a = v^2/r for the centripetal acceleration. To calculate the overall acceleration at any point is somewhat involved, because the portion of gravity that contributes to the centripetal acceleration is varying as a function of theta (or as a function of time, if you prefer). However, it's not too difficult to calculate the maximum g-forces experienced (at the bottom of the arc). As it turns out, I'm actually making an infographic about this right now.