Propagation of Uncertainty - Hollow Cylinder

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The discussion centers on calculating the propagation of uncertainty for the volume of a hollow cylinder using partial derivatives. The user provides specific measurements for height, outer diameter, and inner diameter, along with their uncertainties. They express difficulty in applying the concept to a multi-variable function, as most examples encountered involve simpler operations. Forum members clarify that while they cannot provide a complete solution, they can offer hints and guidance on approaching the problem. The conversation emphasizes the need for the user to demonstrate their understanding and efforts in solving the problem.
Godisnemus
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Hi, I'm having quite a bit of trouble finding the propagation of uncertainty (using partial derivatives) of the volume of a hollow cylinder. The examples in my tutorial only demonstrates how to find the propagation of uncertainty on simple operations such as x + y, x/y, etc...

1. Homework Statement


Height: h = 10.05 mm ; Δ h = +- 0.05 mm

Outer Diameter: D = 6.03 mm ; Δ d = +- 0.05 mm

Inner Diameter: d = 3.01 mm ; Δ d = +- 0.05 mm

Homework Equations



Volume: V = (Pi/4) ((D^2) - (d^2)) (h) = 215.49mm

The Attempt at a Solution


[/B]
As I've stated above, I have no idea how to find the propagation of uncertainty for such a function using partial derivatives. I've looked a fair amount of time on the web but nearly every example given does not contain more then a single or double variable function. If somebody could give me a step-by-step on how to do this, I would be extremely grateful. Thank you.
 
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Helpers can't give you a step by step solution here at PF. That's against the forum rules. They can give you hints and suggestions and point out mistakes, but you need to do most of the work and show your efforts.

Suppose this problem had only two variables, say the volume was a function of two variables x and y: V = f(x,y). How would you proceed (in general terms)?
 
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The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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