Help with problem about beads and a hoop

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The discussion revolves around a physics problem involving beads on a hoop, specifically addressing the forces acting on the beads. It clarifies that the normal force (N) acts inward, countering the outward force exerted by the beads. Participants confirm understanding of the first part of the problem while seeking assistance with the second part. The conversation emphasizes the importance of recognizing the direction of forces in the context of the problem. Overall, the thread highlights collaborative problem-solving in physics.
newcool
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Thanks for the help
 
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newcool said:
Consider this problem:

http://www.physics.harvard.edu/probweek/prob35.pdf

The solution is here:

http://www.physics.harvard.edu/probweek/sol35.pdf


Why is N and mg *\cos\thetaboth positive? I thought N point away from the hoop

No N is inward. The beads try to go outward, but the loop pulls them inward.
 
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Thanks, I got the first part, anyone have any idea bout the second?
 
newcool said:
Thanks, I got the first part, anyone have any idea bout the second?

Yes, the second part looks right to me.
 
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