quiz18_solution

quiz18_solution - Ans: Let theta be the angle made by the...

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04/11/08 Physics 201 Quiz 18 A lever of length L is to be used to lift a mass M at the end of the lever. The pivot point of the lever is a distance d from the end of the lever, and a height h off the ground. Calculate the force (assumed vertical) required at the other end of the lever in order to lift the mass. Calculate the work done in lifting the mass as high as possible.
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Unformatted text preview: Ans: Let theta be the angle made by the lever with respect to the horizontal. Then the torque balance gives Mgd cos(theta)=F(L-d) cos(theta) or F=Mgd/(L-d). If y is the vertical distance that the force acts over, then using similar triangles: d/h = L/y so y=Lh/d Then the work done by the force is W=Fy = MgdLh/((L-d)d) = MgLh/(L-d)...
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This note was uploaded on 03/06/2010 for the course PHYSICS 201 taught by Professor Walker during the Spring '08 term at Wisconsin.

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