I've been reading some pages on the Internet talking about how to implement rotational dynamics in computer games using Angular Momentum and Linear Momentum, however there's one major thing which really doesn't seem to make sense... Let's say I have a pencil lying horizontally - if I hit it with a quick force (well, Impulse) in the middle of F Newtons, it gets an acceleration of a=F/m Now if I hit it off-centre with the same force (/Impulse), it also gets an acceleration of a=F/m, however it's now got angular acceleration too. So it's got MORE energy! It's moving and it's spinning Where the hell did the extra energy come from? I applied the same force in both cases? This is messing with my head... where the hell did the extra energy come from?