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yang09
Feb15-11, 03:42 PM
1. The problem statement, all variables and given/known data
Perform the calculation and report answer in proper scientific notation with absolute uncertainty

73.936(+ 0.19%) / [(0.00455+ 0.00096) + (0.011889(+0.73%))]

2. Relevant equations

Addition/Subtraction:
Absolute uncertainty = square root(uncertainty1 + uncertainty2)
Relative uncertainty = Absolute uncertainty divided by answer to addition(or subtraction)

Multiplication/Division:
Relative uncertainty = (uncertainty divided by corresponding value)2

3. The attempt at a solution

How would I do the absolute uncertainty since there is both subtraction and division?
1. The problem statement, all variables and given/known data



2. Relevant equations



3. The attempt at a solution

chemisttree
Feb15-11, 05:03 PM
Do the addition first and determine the uncertainty for the part solution. Then, using that uncertainty, divide and use the proper rule to determine the uncertainty in the result.

yang09
Feb15-11, 06:35 PM
But after I find the uncertainty for the addition,it is going to be the absolute uncertainty.Would I use the absolute uncertainty when calculating the division part? Or would I have to calculate the relative uncertainty for the addition part and use that for the division part? The thing that is confusing me is which uncertainty to use for the division part, the relative or absolute uncertainty from the addition part.
Would I use the absolute uncertainty because when finding the uncertainty through division, the absolute uncertainty calculation always comes first before the relative uncertainty
Thanks