Hi, I'm having trouble understanding this attached example in my physics textbook. It notes torque as being positive when substituted back into mg-Ft=-ma rather than being negative which I would think it would be because it is going in the clockwise direction. Can anyone help me understand why this is? Ex: String is wrapped around a uniform solid cylinder (like a yo-yo) of mass M and radius R, and the cylinder starts to fall from rest, find the acceleration: They do Ftension-mg=-ma (which I understand) And then look for torque: torque=Ftension*R=I*angular acceleration. <-- This is where I diverge from what they do since I did torque=Ftension*R= - I * angular acceleration They end up with ⅔ g, and I get 2g. Their answer obviously makes more sense so I don't understand why torque would be positive. Also by the way, I is 1/2MR^2 Thank you for any help!