Horizontal Force on Pivot Point

AI Thread Summary
The discussion revolves around calculating the horizontal force on a pivot point in a physics problem involving torque and angular momentum. The user successfully completed part A but struggles with part B, specifically in deriving the required equation. They recognize that the force at the pivot point equals F0 when the distance X is half the length of the rod. A helpful hint suggests taking moments about the center of mass and applying the concept of impulsive torque to relate it to angular momentum. The conversation emphasizes the importance of understanding torque and its application in solving the problem.
Epif
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Homework Statement


http://img151.imageshack.us/img151/6641/torquebk4.jpg


Homework Equations



T=F*r
F*X=Ia
I=ML2/3

The Attempt at a Solution


I was able to do part A easily enough, but I'm not quite sure where to even start with part B. I know that the force on the pivot point would be F0 if X was .5L, ie the center of mass. However, I am unable to come up with the equation asked for. Thanks for any help!
 
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Hi Epif! :wink:

Hint: take moments about any point on the rod (might as well use the c.o.m.), and use "impulsive" torque = change of angular momentum. :smile:
 

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