Chapter 2: Movement And Problem Solving
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2.1
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Measuring Global Temperatures
Units are extremely important in reporting and working scientific measurements,
and they must always be included.
Scientists agree to a standard way of reporting measured quantities in which the
number of reported digits reflects the precision in the measurement—more digits,
more precision; fewer digits, less precision.
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2.2
o
Scientific notation: writing large and small numbers
Scientific notation:
a system used to write very big or very small numbers, often
containing many zeros, more compactly and precisely. A number written in
scientific notation consists of a decimal part and an exponential part (10 raised to
a particular exponent).
Decimal part:
in scientific notation, a number that is usually between 1 and 10
Exponential part:
in scientific notation, 10 raised to an exponent
Exponent:
the part in scientific notation resembling how many places after the
decimal the number contains
To convert a number to scientif notation, we move the decimal point to obtain a
number between 1 and 10 and then multiply by 10 raised to the appropriate
power.
The exponent is positive if you moved the decimal point to the left.
The exponent is negative if you moved the decimal point to the right.
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2.3
o
Significant figures: writing numbers to reflect precision
Scientific numbers are reported so that every digit is certain except the last, which
is estimated.
Significant digits:
The nonplaceholding digits in a reported measurement; they
represent the precision of a measured quantity
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The greater the number of significant digits, the greater the precision of the
measurement.
Determining the number of significant figures in a number:
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All nonzero digits are significant
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Interioir zeros (seros between two numbers) are significant
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Trailing zeros (zeros after a decimal point) are significant
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Leading zeros (zeros to the left of the first nonzero number) are not
significant. They only serve to locate the decimal point. 0.0005 only has 1
significan digit.
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Zeros at the end of a number but before a decimal point are ambiguous and
should be avoided by using scientific notation.
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 Summer '08
 Haverhals
 Scientific Notation, International System of Units

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