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## Forces Concerning a Rectangular Prism

1. The problem statement, all variables and given/known data
I'm wondering this for any object with moment of inertia I, but I'll ask this question for a rectangle for simplicity and I'm sure I can extend it to general objects.

Say we have a rectangular object (with mass m, height h, and width L) that is attached to a wall by some sort of point support exactly at its corner. If we hold it horizontally then let it go and swing, what is the force that the support exerts on the ruler from right after we let go as it swings? Here's a picture:

2. Relevant equations
Moment of inertia of this rectangle: $\frac{m(h^2 + w^2)}{12} + m((h/2)^2+(w/2)^2) = \frac{m(h^2+w^2)}{3}$

3. The attempt at a solution
I was thinking about concentrating the mass into a point mass at the location of the rectangle's center of mass. This would be like a simple pendulum with starting position at angle $θ$ below the horizontal, where $θ=\tan^{-1}(h/w)$. There would be a force of mg downward, which has a component of mg*sin(θ) in the direction of swinging and a component of mg*cos(θ) pulling on the "string" of the pendulum. The force that the support supplies, in return, would be opposite to and equal in magnitude to this pull. I'm not so sure this is correct though...
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