# Homework Help: Rotational Motion- Pulleys with Friction

1. Oct 8, 2007

### danield

1. The problem statement, all variables and given/known data
Two Masses are suspended from a pulley. The pulley itself has a mas of .20kg a radius of .15m a constant torque of .35 MN due to the friction between the rotating pulley and its axle. What is the magnitude of the acceleration of the suspended masses if m1= .4kg and m2= .8 kg (neglect the mass of the string)
Pulley
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M2 M1

2. Relevant equations
T1= M1G - M1A
T2= M2G + M2A
Torque= FL = Moment of Inertia x Alpha,
I= 1/2 mr^2

3. The attempt at a solution
I have tried solving this by solving for A when T2-T1= I alpha, but i really dont know how to apply the fact that the tension is different of both cords due to the friction on the pulley im stuck...

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2. Oct 8, 2007

### danield

I have tried everything... but still i cant get to the answer.. i get to the formula a=(m2-m1)g/(1/2M+m1+m2) but after that i dont know how to apply the torque... :( need help

Last edited: Oct 8, 2007
3. Oct 8, 2007

bump....