My answer (posted below) was deleted from the following question: Calculating mass of unknown object using center of mass. The deleter's comment read,
"I'm deleting this in accordance with our homework policy. Please do not give complete or near-complete answers to homework-like questions."
Answer:
You don't really need torque equations. Just treat the object as a point mass, and use the following equation for CoM: $$x_{\rm CoM}=\dfrac{mx+MX}{m+M}$$ where m, x, M and X represent the mass of the stick, position of the stick's CoM, the mass of the object, and the position of the object's CoM (all positions relative to 1 fixed point).
All I did was provide an equation that is present on the first page of every textbook section relating to the center of mass of two points. And yet this is a 'complete' or 'near complete' answer.
The OP's question read, "How exactly would you go about solving this. I know the answer should be roughly about 108 grams but am unsure how to set up the equation."
OP did not ask for an answer. OP asked for a) general approach, and b), setting up the equation.
The general approach is the CoM method for a), and for b), I gave out the standard textbook equation. Furthermore, this problem is of interest to more than OP, as the approach is pretty standard in these introductory problems.
There is still quite some work for OP to do; associate the positions of the masses correctly relative to some origin which is yet to be identified, figure out the connection between a rigid body's CoM and how it plays into a system of particles, and, of course, solve for the mass. If I were to provide a complete answer to this question, mine would start with the provided equation.
Thus, I don't see how my answer constitutes a 'complete' or 'near complete' solution. I thought I left enough work for OP.
What makes the answer complete?
