Find the Angular Acceleration, acceleration and friction force extered

AI Thread Summary
The discussion revolves around calculating the angular acceleration, linear acceleration, and friction force for a circular disk with specific dimensions and applied forces. The user initially set up equations based on free body diagrams but faced challenges due to having more unknowns than equations. They realized that the vertical acceleration is zero, allowing them to incorporate the friction force equation related to static or kinetic friction. Ultimately, the user successfully solved the problem after clarifying their approach. The thread highlights the importance of correctly identifying constraints in mechanics problems.
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Homework Statement


The circular disk of 595-mm radius has a mass of 16 kg with centroidal radius of gyration = 500 mm and has a concentric circular groove of 220-mm radius cut into it. A steady force T is applied at an angle θ to a cord wrapped around the groove as shown. If T = 41 N, θ = 39°, μs = 0.23, and μk = 0.19, determine the angular acceleration α of the disk, the acceleration a of its mass center G, and the friction force F which the surface exerts on the disk. The angular acceleration α is positive if counterclockwise, negative if clockwise; the acceleration a is positive if to the right, negative if to the left; and the friction force F is positive if to the right, negative if to the left.

I have attached an image of the question

Homework Equations



rs is the smaller radius of 220 mm

rL is the larger radius of 595 mm

I = k2
m

The Attempt at a Solution



I started off by drawing a FBD of the circular disk, in which I included the forces of T, mg, N (normal force) and F (friction force)

ƩFx: max = Tcos(θ) - F

ƩFy: may = Tsin(θ) - mg + N

ƩMG: IGα = Trs - FrL

So, now I have three equations but 5 unknowns: ax, ay, F, N and α. How do I find the other two equations?

EDIT:

I've just realized that ay = 0. So, could I use F = u*N, where u would be the kinetic of static friction, as the fourth equation?
 

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Yeah, I jumped the gun a bit.

It looked more complicated than it was. I've solved it now. Thanks
 
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