Lever Word ProblemDate: 01/14/2003 at 21:30:06 From: Purdy Skwakins Subject: Lever word problems If a person has a 3-foot wrecking bar and places a fulcrum 3 inches from one end, how much can he lift if he applies a force of 50 pounds to the long end? Date: 01/16/2003 at 10:38:38 From: Doctor Ian Subject: Re: Lever word problems Hi Purdy, The key idea is that the amount of work is the same on both ends of the lever. And work is equal to force times distance. So let's say he moves the long end of the lever by 1 foot. The total work is 50 lbs times 1 foot, or 50 ft-lbs. How far will the other end of the lever travel? You can use similar triangles to figure that out. Whatever it turns out to be, the work on each side, force * distance = force' * distance' will have to be the same. So if you know force, distance, and distance', you can use that to find force'... which will tell you how much you can lift. Does that make sense? - Doctor Ian, The Math Forum http://mathforum.org/dr.math/ |
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