Ratational Dynamics- PLEASE HELP

[Omlette]

Homework Statement

A small 650 gram ball on the end of a thin light cord is rotated in a horizontal circle of radius 1.2 m. Calculate the torque needed to keep the ball rotating at a constant angular velocity if air resistance exerts a ofrce of 0.020 N. Ignore the rod's moment of intertia and air resistance.

Homework Equations

T= Ia(alpha)

The Attempt at a Solution

Well I found the moment of inertia but I am stuck on where to go next. Please help me!

 

[olgranpappy]

calculate the torque due to the air resistance using your other equation for torque