Answer: Calculating Relative & Absolute Uncertainty of R^-2

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The discussion focuses on calculating the absolute uncertainty of R raised to the power of negative two, given a distance measurement of 4.000±0.002 m. Participants clarify that the absolute uncertainty is 0.002 m, but there is confusion about whether the question pertains to absolute or relative uncertainty. It is suggested that to find the relative uncertainty, one must divide the absolute uncertainty by the measured value. The conversation highlights the need for clarity in distinguishing between absolute and relative uncertainties in calculations. Understanding these concepts is crucial for accurately interpreting measurement uncertainties.
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Absolute Uncertanity

Homework Statement


A distance R is measured to be 4.000±0.002 m
What is the absolute uncertainty in R to the power of negative two?


Homework Equations





The Attempt at a Solution



4^-2 = 0.00625
0.002^-2 = 250000

Im stuck at this question I have no idea where to go, any help would be appreciated!
 
Last edited:
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umm you already gave the absolute uncertainty, it is 0,002m...
 
but I tried that, meaning 0.002 and that's not it, I also tried 250000 (using SI) and that isn't correct either...not really sure where to go...
 
Are you looking for the absolute or relative uncertainty? as in the thread title you say relative, but then in the problem description you say absolute.

The absolute is 0.002m that is 100%, then most probably you are looking for the relative uncertainty.
That is divide the absolute by the average.
 
sorry for the confusion, the question is as follows:
What is the absolute uncertainty in R to the power of negative two?

but wouldn't you have to do something to the +-0.002m?
 
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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