Zero Torque and Static Equilibrium pulley problem

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To solve the static equilibrium problem involving a pulley with two different masses, it's essential to recognize that the tensions in the string will not be equal due to the differing weights. The total torque acting on the pulley must equal zero for static equilibrium to be achieved, which means the frictional torque must counterbalance the difference in tensions. The torque can be calculated using the formula torque = Fr sin(theta), where F is the force (tension) and r is the radius of the pulley. In this case, the angles are assumed to be 90 degrees, simplifying the calculations. Understanding these principles is crucial for determining the necessary frictional torque in the system.
just.karl
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A string that passes over a pulley has a .301kg mass attached to one end and a 0.635 kg mass attached to the other end. The pulley, which is a disk of radius 9.50cm, has friction in its axle. What is the magnitude of the frictional torque that must be exerted by the axle if the system is to be in static equilibrium?

I know I have to figure out the torque required by the axle to get both tensions equal. But I don't know what equations you use to figure out the torque with two masses on each side.


Thanks
 
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just.karl said:
I know I have to figure out the torque required by the axle to get both tensions equal.

No, the tensions will not be equal. total torque will be zero. Two different tensions will be applied to the wheel at the given radius. The angles are assumed to be 90 degrees, since both masses will hang down (safe assumption).

torque = Fr sin(theta)
 
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