Transcript Chapter Prologue: Science Skills

The Metric System
Catherine Le (Ilona Davies)
The Harker School
2007-2008
Brief History of Measurement
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The Metric System
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SI Units of Measurement: Metric System

Scientists all over the world use a set of measuring units called
the International System of Units (SI).
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SI is a revised version of the metric system, which is based on
multiples of 10.
SI is built upon seven base units and many derived units.

For example, the base unit for length is meter (m) and the derived unit
for volume (length x length x length) is cubic meters (m3).
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SI Base Units (Video Review)

Length

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Volume

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Meter (m)
Liter (L or l)
Mass

Gram (g)
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SI Base Units
http://www.onlineconversion.com/
Reference: http://physics.nist.gov/cuu/Units/index.html
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Examples of SI Derived Units
Quantity
Unit
Symbol
Area
square meter
m2
Volume
cubic meter
m3
Speed
meters per second
m/s
Acceleration
meters per second squared
m/s2
Force
newton
N = kg.m/s2
Energy
joule
J = kg.m2/s2
Pressure
pascal
Pa = kg/m.s2
Density
Grams per cubic centimeter
g/cm3
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Metric System of Measurement

Measurements must have a value and a unit (for example, 53
meters).
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A metric prefix indicates how many times a unit should be
multiplied or divided by 10. For example, 1000 meters = 1
kilometer.
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The prefix “kilo-” tells us that we need to multiply km by 1000 to
convert to m.
A conversion factor is a ratio of equivalent measurements that
is used to convert a quantity of one unit to another.
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To convert s to ms, you would multiply by a conversion factor of 1000
ms/1 s.
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Some SI Prefixes
Prefix
Factor
Prefix
Example
mega-
106
M
Megameter (1 000 000 meters)
kilo-
103
k
Kilometer (1000 meters)
hecto-
102
h
Hectometer (100 meters)
deka-
101
da
Decameter (10 meters)
100
Meter (1 meter)
deci-
10-1
d
Decimeter (0.1 meters)
centi-
10-2
c
Centimeter (0.01 meters)
milli-
10-3
m
Millimeter (0.001 meters)
micro-
10-6
µ
Micrometer (0.000 001 meters)
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Metric Conversions
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Metric Conversions
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Metric Stairs
UP
RULE
Kilo
Decimal Moves Left
one place for each
step you go up.
Hecto
Deca
Base
Unit
(Meter
Liter
Gram)
Deci
Centi
Milli
Decimal Moves
Right one place
for each step you
go down.
DOWN
RULE
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Checkpoint!
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What is the numerical value of the following prefixes?
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Deci = ________________
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Hecto = ________________
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Milli = ______________
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Deca = ________________
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Kilo = ___________________
What is the unit of measurement for the following?
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Length = _________________
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Volume = _________________
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Mass = ________________
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Checkpoint!
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1 km = ____________ m
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1 m = ____________ cm
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1 mm = ____________dm
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1 dm = ____________ dam
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1 liter = ____________ cm3 (Hint: 1mL = 1 cm3)
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1 kg = ____________ g
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