Moment of inertia of solid slab

[songoku]

Homework Statement

Solid slab with moment of inertia 2 kg m² is given the forces as shown.

Find the angular acceleration if θ = 37°, R1 = 10 cm, R2 = 25 cm

Homework Equations

τ = I . α

The Attempt at a Solution

This is what I've tried although I don't know it is correct or wrong; I tried to find all the torques by the 4 forces.
τ₁ = 10 x R2 (clockwise)
τ₂ = 10 x R1 (anti-clockwise)
τ₃ = 20 x R1 (anti-clockwise)

I can't find the fourth torque because I don't know how to find the perpendicular distance from the inclined-10 N force to the center. Please help

Thanks

 

[cupid.callin]

Hint: You can resolve it into 2 components: tangential and radial

 

[songoku]

Hint: You can resolve it into 2 components: tangential and radial

Sorry I don't get it. The arrow of the force is "toward" the slab, not "away" from it so if I resolve the force, I will get 10 cos θ and 10 sin θ but I don't see that one of them is tangential and one of them is radial.

 

[cupid.callin]

Sorry I don't get it. The arrow of the force is "toward" the slab, not "away" from it so if I resolve the force, I will get 10 cos θ and 10 sin θ but I don't see that one of them is tangential and one of them is radial.

You are right, one of them won't actually be radial

But since the blue distance is no given so i assume that its the imperfection of the figure causing the problem.
If you have a way of finding the blue distance the its good or else IMO you can call it radial ...

 

[songoku]

You are right, one of them won't actually be radial

But since the blue distance is no given so i assume that its the imperfection of the figure causing the problem.
If you have a way of finding the blue distance the its good or else IMO you can call it radial ...

OK I think I get it. Thanks for your help :)