A seizure of heroin is analyzed to obtain the %purity of the drug. An intermediate calculation involves the weight of the sample which is recorded at 75.54 mg. The balance uncertainty is 0.31 mg.
What is the relative uncertainty of the sample weight reported to two significant digits?

Question

Quizplus · Accepted Answer

The relative uncertainty is calculated by dividing the absolute uncertainty by the measured value and is often expressed as a fraction or percentage. Here, it's $ \frac{0.31 \, \text{mg}}{75.54 \, \text{mg}} = 0.0041 $ when rounded to two significant digits.

A Seizure of Heroin Is Analyzed to Obtain the %Purity