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LiftHeavy13
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http://dev.physicslab.org/Document....taryMotion_RotationalDynamicsPivotingRods.xmlin this example, the rod is swinging with one end pivoted. conservation of energy was used in this example. the change in potential energy was converted to kinetic energy, and mechanical energy thus was supposedly conserved. However, I have a problem with this: the net work done on a body F(dot)d where at least a component of a force acts on a body in the same direction as the direction of the center of mass' movement. the pivot point exerts a force perpendicular to the rod (and therefore parallel to its center of mass' velocity vector), thus doing work on it... so how can mechanical energy be conserved? this makes no sense