How Can Torque Determine the Weight of an Unknown Object?

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1. Homework Statement
Torque is used to determine the weight of an object. A 10.0 m long pole weighing 20.0 N has its center of gravity 2.00 m from one end. An object of unknown weight is hung at the end opposite the center of gravity. With the object hanging at this end, the pole now balances 2.00 m from the unknown weight. What is the weight of the unknown weight? 2. Homework Equations
T = F * R3. The Attempt at a Solution
T = 20 * 2
= 40 ?

 

[Bill Foster]

T_1=T_2

F_1 R_1=F_2 R_2

Solve for F_2