Physics Help Forum Minimum power

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 Oct 24th 2008, 09:04 AM #1 Member   Join Date: Jul 2008 Posts: 60 Minimum power Hey, guys. I have this guy trying to lift this cylinder pass the step with minimum force and so is the question, what's the minimum power that he needs to use and at what angle (alpha)? I also added the solution. The thing I don't understand is, why when the momentum of the weight and the momentum of the force equal one to another, you can say that the force is minimum? I mean, I can understand that there's no angular acceleration, but why is it minimum (the force)? 10x. Attached Thumbnails
Oct 24th 2008, 06:57 PM   #2
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 Originally Posted by asi123 Hey, guys. I have this guy trying to lift this cylinder pass the step with minimum force and so is the question, what's the minimum power that he needs to use and at what angle (alpha)? I also added the solution. The thing I don't understand is, why when the momentum of the weight and the momentum of the force equal one to another, you can say that the force is minimum? I mean, I can understand that there's no angular acceleration, but why is it minimum (the force)? 10x.
Consider something in linear motion. When we have to lift a weight, if I supply a force upward with magnitude less than the weight, what happens? The block does not move upwards unless my applied force can balance the weight.I guess it is similar to the thing you've suggested

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