Quote:
narf poit chez BOOM said:
Excuse me, but if I push on a block of wood and you push on a block of wood and we both have equal strength, given your arguement, neither of us would be expending energy. However, I think in half an hour you would say otherwise, no mater how balanced the forces are. 
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Erm... the difference is that the refridgerator expends 0 energy to hold the magnet in place. The point was that not _all_ stationary objects require energy to remain stationary. Certainly, you can waste energy on an object that doesn't move in the end, but that is not the same thing. When pushing a block that isn't moving, you are not transfering any energy to it. The force you apply is not enough to overcome the counterforces involved, so no work is done on the block. As a result, its energy does not change. You have used energy, but that is for an entirely different reason. It requires a constant source of energy to keep your muscles contracted.