ok this was a problem in my book and the answer apparently is 29N.(adsbygoogle = window.adsbygoogle || []).push({});

I have the diagram and pictures below. I know that the pivot point will be the edge of the block that is touching the outside of the wheel. When the wheel is in equilibrium the sum of the torque will=zero so i can set up the equation where the sum t=force times lever arm(l). When the wheel rises the normal force will equal zero. I am having major trouble getting the lever arms though. I know how to do vectors but I dont have any angles to work with so I am just trying the use the radius. Any guidance would be greatly appreciated.

http://img7.imageshack.us/img7/3214/mmspicture1p.jpg [Broken]

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here is my diagram

http://img641.imageshack.us/img641/7379/001aoz.jpg [Broken]

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# Homework Help: (torque) a force needed for wheel to rise up onto box

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