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Homework Statement
Determine the angular acceleration of the uniform disk if (a) the rotational inertia of the disk is ignored and (b) the inertia of the disk is considered. The system is released from rest, the cord does not slip on the disk, and bearing friction at O may be neglected. The angular acceleration is positive if counterclockwise, negative if clockwise.
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Homework Equations
The Attempt at a Solution
m1 = 1.5 kg
m2 = 3.1kg
r = 0.32m
I started by summing the moments about O
ƩM_{O} = (m1gr + m2gr)/I_{O}
I_{O} = 2mr^{2} but I'm not sure why this is the case. A classmate of mine said something about adding in the inertias from the weight but I'm not sure what this means.
Also, how to I account for the disk inertia?
Any advice would be appreciated.
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