Chpt 3 : Review Flashcards
Measurement
is the act of comparing an unknown quantity to a standard unit of measurement
Dimension
In science is a property that can be measured.
Instruments
Is any artificial device made for the purpose of refining, extending, or substituting for the human senses when measuring.
Unit
Is the segment of a dimension assigned a value of 1 for measuring purposes.
Observational bias
Is a flawed perspective on data that results from a person’s desire to see a certain outcome or from one’s limitations.
Measured data has two parts:
a number that gives the size of the measurement and the dimensional unit.
Metric system of measures
In 1799 France established a decimal metric system of measures consisting of the meter (m) and the kilogram (kg).
Cubic decimeter
Is equal to 1/1000 of a cubic meter
Prefix
Each prefix indicates the factor necessary to produce the required unit
Conversions factor
Is any factor equal to 1 that consists of a ratio of two units.
Conversion check
If the new unit is larger than the original unit, then the new number will be smaller than the original number.
≅
“approximately equal to.”
The measurement error
is the mathematical difference between the measured value and the actual value.
Accuracy
Evaluates how close a measurement is to the actual value.
Precision
evaluates how exactly a measuremen t is made.