Calculating Volume With Center of Mass

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To calculate the volume of a solid formed by rotating a function f(x) around the x-axis, one can use the Theorems of Pappus, specifically the formula 2πAȳ, where A is the area between the curves and ȳ is the centroid of that area. The centroid and center of mass can be similar in certain contexts, but they are not always the same. Clarification is needed on whether the focus is on the centroid of a volume or the center of gravity of a mass. Understanding these distinctions is crucial for accurate calculations. This method effectively links geometry and calculus in determining volumes of revolution.
iRaid
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I remember seeing a way to do this, can someone link me to some relevant material or post a proof and equation?

Thanks
 
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Your request is a little ambiguous. Do you want to calculate the centroid of a volume or do you want to calculate the center of gravity of a mass? The two may not necessarily be the same.
 
SteamKing said:
Your request is a little ambiguous. Do you want to calculate the centroid of a volume or do you want to calculate the center of gravity of a mass? The two may not necessarily be the same.

I'm sorry. I mean: given a function, f(x) and rotating it around the x-axis. Can you find the volume of this function using the centroid/center of mass (I was told these are the same...)?
 
You want to look up the Theorems of Pappus.
 
So it is:
2\pi A\bar{x}
Where A is the area between 2 curves and x bar is the center of mass.
 
x-bar is the centroid of the area being revolved, measured with respect to the axis of revolution.
 

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