Posted by Papito on .
A uniform solid disk with a mass of 40.3 kg and a radius of 0.454 m is free to rotate about a frictionless axle. Forces of 90.0 N and 125 N are applied to the disk
(a) What is the net torque produced by the two forces? (Assume counterclockwise is the positive direction
(b) What is the angular acceleration of the disk?
This is how i solved it.
Torque = Fl
net torque = (125N x 0.454m) + (90N x 0.454N)=97.81
Angular acceleration = torque/ inertia
Inertia = mass x radius ^2
= 40.3 kg x 0.454 ^2 =8.31
Angular acceleration = 97.81/ 8.31 =11.77 rads/s^2
Please check solution
Isnt the moment of inertia 1/2 m r^2 ?
So Moment of Inertia = 0.5x 40.3kg x 0.454^2 = 4.15
Angular acceleration =97.81/4.15