Newton's 2nd Law - Rotation, Torque, Disk

[VitaX]

Homework Statement

Homework Equations

Newton's 2nd Law F = ma
Torque Equation τ = Iα

The Attempt at a Solution

Well I know I have to write separate equations for the masses and tensions so I got this:
T1 - m1g = m1a
T2 - m2g = -m2a -----> (negative because acceleration downwards is negative)
How do I write Newton's 2nd Law for the disk and relate it to the two equations above so I'm able to solve for the magnitude of acceleration and the two tensions?

 

[tiny-tim]

Hi VitaX!

Newton's 2nd Law F = ma
Torque Equation τ = Iα
…
How do I write Newton's 2nd Law for the disk and relate it to the two equations above so I'm able to solve for the magnitude of acceleration and the two tensions?

Your τ = Iα is instead of Newton's 2nd Law …

just convert T₁ and T₂ into torque (and a into angular acceleration)

 

[VitaX]

Hi VitaX!


Your τ = Iα is instead of Newton's 2nd Law …

just convert T₁ and T₂ into torque (and a into angular acceleration)

Yeah I asked for some help from a dude on msn and was able to write the equation. Ended up being T2R - T1R = .5MR^2(a/R)