A QUICK WAY TO WRITE REALLY, REALLY BIG OR REALLY, REALLY SMALL
NUMBERS. Scientific Notation
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Rules for Scientific Notation To be in proper scientific
notation the number must be written with a number between 1 and 10
and multiplied by a power of ten 23 x 10 5 is not in proper
scientific notation. Why?
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137,000,000 can be rewritten as 1.37 X 10 8
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Using scientific notation, rewrite the following numbers.
347,000. 3.47 X 10 5 902,000,000. 9.02 X 10 8 61,400. 6.14 X 10
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Examples How many mm in a Meter? 10 3 mm How many g in a Gram?
10 6 g How many ns in a Second? 10 9 ns How many km in a Meter? 10
-3 km
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SI Units Fundamental Quantities Length = Meters (m) Mass =
Kilograms (Kg) Time = Seconds (s) Found through direct measurement
Building blocks for the SI measurement system. Is Volume a
fundamental Quantity?
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Base vs. Derived Units Derived Units are constructed through
combinations of base units Usually base units multiplied/divided to
develop these Derived units supported by physics formulas Velocity
(rate) = Distance / Time so velocity units = m / s
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Metric Conversions
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The Factor label Method A way to solve math problems in physics
Used to convert km to miles, m to km, N to g, g to N, etc. To use
this we need: 1) desired quantity 2) given quantity 3) conversion
factors Conversion factors are valid relationships or equalities
expressed as a fraction and equal to one!
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Equalities State the same measurement in two different units
length 10.0 in. 25.4 cm
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Conversion Factors Fractions in which the numerator and
denominator are EQUAL quantities expressed in different units but
always equal to one. You can always multiply any equation by this
equality and not change the quantity, just the units. Example: 1
in. = 2.54 cm Factors: 1in. and 2.54 cm 2.54 cm 1 in.
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For example: 1 km = 0.6 miles the conversion factor is Write
conversion factors for 1 foot = 12 inches What conversion factors
can you think of that involve meters?
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Conversion Factors Conversion factors for 1 ft = 12 in There
are almost an infinite number of conversion factors that include
meters:
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Factor label Example How many kilometers are in 47.0 miles?
(note: 1 km = 0.621 miles) First write down the desired quantity
Write down given quantity Write down all conversion factors
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More Examples 1. You want to convert 100.00 U.S. dollars to
Canadian dollars. If the exchange rate is 1 Can$ = 0.65 US$, how
much will it cost? # Can$ = 100.00 US$ x 1 Can$ 0.65 US$ = 153.85
Can$
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Learning Check Write conversion factors that relate each of the
following pairs of units: 1. Liters and mL 1 Liter = 1000 mL 2.
hours and minutes 1 hour = 60 minutes 3. meters and kilometers 1000
meters = 1 kilometer
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How many minutes are in 2.5 hours? 2.5 hr x 60 min = 150 min
2.5 hr x 60 min = 150 min 1 hr 1 hr By using dimensional
analysis/factor-label method, the UNITS ensure that you have the
conversion right side up, and the UNITS are calculated as well as
the numbers!