How Do You Calculate the Force Needed to Turn a Handle in a Pulley System?

[MischaHam]

i have a simple pulley with a mass a one side and turning handle at the other. i can calculate the tension in the pulley but i am not sure how to calculate the force required to turn the handle and move the mass, or is this simply just equal to the tension in the system?

 

[RevMatcher]

Assuming your turning handle looks like this:
http://www.midcurrent.com/news/images/Cranky%20winding%20high%20res.jpg

To calculate the force required to keep the handle in place (F_0), do a moment balance calculation about the center of the turning handle. (summation of moments = zero). To move the mass, the force applied will thus have to be greater than F_0.

 

[Bob S]

You need force (Newtons) to lift the mass. You need torque (Newton-meters) to turn the handle.

Bob S