Significant Digits by 4k75yts4

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									Significant Digits




    What are they?
    And
    How do you use them?
Accuracy:

 This is the concept which deals with whether a
  measurement is correct when compared to the known
  value or standard for that particular measurement.
 When a statement about accuracy is made, it often
  involves a statement about percent error.
 Percent error is often expressed by the following
  equation:
 % error = (|experiment value - accepted value| /
  accepted value) x 100%
 Also see Problem Set # 1-14 in the workbook
Precision:

 This is the concept which addresses the degree of
  exactness when expressing a particular measurement.
 The precision of any single measurement that is made
  by an observer is limited by how precise the tool
  (measuring instrument) is in terms of its smallest unit.
 How would you divide the following 1 meter long bar up
  into smaller divisions? Why? What would your choice
  have to do with precision?

                     1 METER BAR
Precision and Measuring:
Significant Digits:
When someone else has made a
 measurement, you have no control over
 the choice of the measuring tool or the
 degree of precision associated with the
 device used.
You must rely on a set of rules to tell you
 the degree of precision.
Refer to the “Rules for determining when
 zeros are significant” (PS#1-9, workbook)
Significant Digits in Math:

Use PS#1-10 to check your understanding
 of identifying significant digits in
 measurements.
See PS#1-11 for the rules about using
 significant digits in addition and
 subtraction.
See PS#1-11 for the rules about using
 significant digits in multiplication and
 division. Then go on and do PS#1-12.

								
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