Atwood machine with two holes in pulley.

[AbigailM]

Homework Statement

A system consists of a pulley and two masses m1, m2 haning from it as shown in the figure. The pulley is a disk of radius R with constant mass density that has two circular hole with radius R/2. Find the angular acceleration of the pulley.

Figure attached.

Homework Equations

L=T-U
$I=I_{cm}+mh^{2}$

The Attempt at a Solution

The solution is attached.

I'm not interested in knowing if my calculation for the moment of inertia is correct which is found at the bottom of the solution.

 

[TSny]

In the first equation for I at the bottom of the page, shouldn't the last term be negative? (Never mind, I missed seeing a set of parentheses!)

It all looks good to me.

 

[AbigailM]

Ooops I made a typo. I meant to say that I'm interested in knowing whether or not my moment of inertia is correct.

Oh cool TSny you read it how I meant it.