Conversion Factors and Dimensional Analysis
Many times the need arises to change the units of a quantity or measurement
to different units.
The new units may be in the same measurement system as
the old ones (meters to kilometers) or they may be in a different system
(meters to inches, or minutes to hours).
Conversion Factor
: an equality, expressed in fractional form, that is
used as a multiplier
to convert a quantity in one unit to a quantity in
another unit.
Dimensional Analysis
: the mathematical tool used to change units.
Unit conversion is accomplished by multiplying a given quantity or
measurement by one or more conversion factors.
Given quantity x conversion factors(s) = desired quantity
Notes on conversion factors:
1.
Multiplication by one or more conversion factors does not change the
value of a measurement or quantity because all conversion factors have a
numerical value equal to one.
Multiplication by the number one does not
change the value of an expression.
2.
A fixed relationship between two quantities allows one to construct a
pair
of conversion factors.
From the relationship: 1 minute = 60 seconds we obtain the following pair of
conversion factors:
(a)
minute
1
seconds
60
(b)
seconds
60
minute
1
The first conversion factor (a) is used to convert minutes into seconds.
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 Winter '11
 HENSHAW
 Scientific Notation, SI prefix, Kilogram, Exponentiation

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