Conservation of angular momentum

vendredi 30 mai 2014

If a person hangs still from a rope some distance above water and then the rope is cut off, is it possible for the person to start somersaulting in the air before hitting the water? When I try to imagine myself in this situation, I would think that "of course it is, one can just start moving in the air to start rotating". But according to the principle of conservation of angular momentum, it is not possible, since it says that when the sum of average external torques is 0 then pf = p0 <=> I*wf = I*w0 and in this case w0=0 so that means wf must also be 0.



When a physical law goes against intuition like this, I find it hard to understand. Although I don't have the ability to try the experiment myself at the moment, I would definately imagine that it would be possible to start rotating in the middle of the air.



Any ideas how this can be explained in a way that doesn't go against intuition?





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