Surya Adinata Posted August 17, 2014 Report Share Posted August 17, 2014 My chemistry teacher has been teaching us about propagation of error. She thought us that if we sum c=a+b, then Δc=sqrt(Δa^2+Δb^2).(this is according to our Oxford Chemistry Textbook for 2016 syllabus) However, in my physics class, my teacher thought us that if c=a+b, Δc=Δa+Δb. (this is supported by the data booklet.) I've done a research on the internet and found that the former uses standard deviations while the latter uses simpler average errors. So, what should I do with the uncertainties when I sum a and b? Reply Link to post Share on other sites More sharing options...
Guest Aniruddh Posted August 17, 2014 Report Share Posted August 17, 2014 Use the one provided by the data booklet, If you any definitions or formulas that differ between official IB documents and text books/unofficial documents go for the IB documents without a second thought as it will be more valid according to IB at least. Reply Link to post Share on other sites More sharing options...
Vioh Posted August 17, 2014 Report Share Posted August 17, 2014 As far as I know, the correct formula for the propagation of error is Δc=Δa+Δb. In fact, I have never really seen the other formula that you gave. So I recommend you to go with the formula suggested by the data booklet. Plus, i don't really see the connection between standard deviations and propagation of errors at all. I mean standard deviations are often used when you have lots of different values of measurements for a quantity. While propagation of errors only comes in when we operate on values that have uncertainties. Thus, standard deviations and propagation of errors are often used in entirely different contexts. Reply Link to post Share on other sites More sharing options...
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