Weight of Unknown Object: 40 N

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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 $$F_2$$

 

[ogb p]

Your attempt at a solution is correct. The unknown weight must also be 20 N in order for the pole to balance at a distance of 2.00 m from it. This is because the torque exerted by the unknown weight must be equal to the torque exerted by the pole in order for equilibrium to be maintained. Therefore, the weight of the unknown object is 20 N.