What Causes the Net Torque on a Uniform Disk?

[whitesox]

[SOLVED] Net torque of uniform disk

Homework Statement

A uniform disk with a mass of 34.8 kg and a radius of 0.32 m is free to rotate about a frictionless axle. Forces of 90.0 N and 125 N are applied to the disk, as the drawing indicates.

What is the net torque produced by the two forces?

Homework Equations

Torque = rFsin(theta)

The Attempt at a Solution

I've tried using the equation above...125(0.32)sin90 - 90(0.32)sin90 = 11.2 N*m which is wrong. I know this question is trivial, but I'm pretty frustrated at this point...any help would be great.

 

[G01]

Assuming the information given is correct, I agree with you that the magnitude of the torque is 11.2 Nm. My physics text usually considered counterclockwise as positive, with clockwise as the negative direction, so I actually got -11.2Nm. This isn't the problem right? If not I would check that you have the correct information.

 

[whitesox]

Assuming the information given is correct, I agree with you that the magnitude of the torque is 11.2 Nm. My physics text usually considered counterclockwise as positive, with clockwise as the negative direction, so I actually got -11.2Nm. This isn't the problem right? If not I would check that you have the correct information.

It's the correct information, and the answer is -11.2. Thanks.

 

[G01]

Anytime!

 

[j-dawg]

What is the magnitude of the angular acceleration of the disk?