[curiousgeorge1234]

A rather simple question I'm sure, yet I have had trouble finding the answer.

I am required to calculate the % uncertainty.  I do not have an equation for this.  It is spoken of in my text, but there is no equation to use.

Just as an example:  if the following info is given:   uncertainty for the scale is +/- 0.01g, total sample mass #1 is X,  mass of sample #2 is Y, mass of Cu in the sample #1 is W, mass of Cu in sample #2 is Z.

Now, this is what I think the calculation for % uncertainty is:

uncertainty weight/value of weight x 100 = % uncertainty
=0.01/ value of weight x 100 = % uncertainty

If this is the case, for the value of weight, do I pick one sample (ie. X) or do I average the weights of samples 1 and 2 and use that figure?  I'm pretty sure the mass of Cu is not relevant in this calculation.

Am I at least on the right track here?

[chiralic]

You wrote: uncertainty weight/value of weight x 100 = % uncertainty
                0.01/ value of weight x 100 = % uncertainty

Hint: Use parenthesis in yours equations with fractions to avoid confusion

(uncertainty weight of your scale/value of weight) x 100 = % uncertainty

As complement, read this:http://spiff.rit.edu/classes/phys377/uncert.html

Chiralic