1-The laboratory manual specifies two types of errors in measurements. What are
ID: 844487 • Letter: 1
Question
1-The laboratory manual specifies two types of errors in measurements. What are these errors? Briefly describe each kind and provide examples
2-What is meant by the terms (a) accuracy, (b) precision ? Definie and provide examples .
3-Definie the term absolute uncertainty. Give an example
4-Give a definition and an example of relative uncertainty
5- Define density and discuss what it means for this property to be an intrinsic property of material .
6- Look and record the literature values for the densities of aliminum, lead,and steel.
Explanation / Answer
measurement error and instrumental error
accuracy is is the degree of closeness of measurements of a quantity to that quantity's actual (true)value.
precision of a measurement system, related toreproducibility and repeatability, is the degree to which repeated measurements under unchanged conditions show the sameresults
Absolute error or absolute incertainty is the uncertainty in a measurement, which is expressed using the relevant units. Also, absolute error may be used to express the inaccuracy in a measurement.
Examples: If a measurement is recorded to be 1.12 and the true value is known to be 1.00 then the absolute error is 1.12 - 1.00 = 0.12. If the mass of an object is measured three times with values recorded to be 1.00 g, 0.95 g, and 1.05 g, then the absolute error could be expressed as +/- 0.05 g.
Relative uncertainty is a measure of the uncertainty of measurement compared to the size of the measurement
Three weights are measured at 1.05 g, 1.00 g, and 0.95 g. The absolute error is