Transcript The Metric System

The Metric System
-why
do
we
need
to
learn
this?
Metric mishap caused loss of
NASA orbiter
Orbiter
NASA's Climate Orbiter was lost
September 23, 1999
By Robin Lloyd
CNN Interactive Senior Writer
(CNN) -- NASA lost a $125
million Mars orbiter because a
Lockheed Martin engineering
team used English units of
measurement while the agency's
team used the more conventional
metric system for a key
spacecraft operation, according
to a review finding released
Thursday.
We use the “English” system
English system
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Only in the USA and Britain
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No systematic approach
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Based on body parts of the of royalty! And other
Imperial connections…..
Units
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Length = Inches (12 inches = length of King’s foot!!!)
Mass/Weight = Pounds
Volume = Gallons (Queen Anne’s wine gallons!)
Metric or SI System
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Almost every country except USA and Britain
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Systematic approach
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Based on 10’s
Units
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Length = Meters
Mass/Weight = Grams
Volume = Liters
Time = Seconds
Temperature = celsius
Temperature scale of water
Celsius
Fahrenheit
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English system
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Metric System
Boiling point
212°F
Boiling point
100°C
Freezing point
32°F
Freezing point
0°C
Temperature scale
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English system
Body Temp
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98.9°F
Metric System
Body Temp
37°C
Room temp: 25c
Some conversion relationships
for GRAMS:
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1g = 1000 mg can also be written as a
fraction: 1000 mg
1g
OR AS : 1 g
1000m g
Example for Unit Conversions
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1Km = 1000m
1Km = 100000cm
1Km = 1000000mm
1Km = 1000000000 mm
1m = 100cm
1m = 1000mm
1m = 1000000 mm
1cm = 10mm
1cm = 10000mm
1mm = 1000mm
Practice these conversions
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Ex. 1: Convert 46.5 mg to grams.
46.5 mg
1 g
1000 mg
= 0.0465g
Picket Fence Method for Metric
Conversion Problems
What you start with goes here What you need to cancel out What you want to end with
so youget what you want
Practice these conversions
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Ex. 1: Convert 125cm to Km.
125 cm
1 m
1Km 0.00125Km
100 cm 1000m
Kilo
1000X
Hecto
100x
Deka 10x Std unit
Kilometer
1Km=
1000m
Hectometer
1Hm=
100m
Dekameter
1 Dm/dk)=
10m
(abbr. Km)
(abbr. Hm)
(abbr. Dm)
Kilometer
1KL=
1000L
Hectometer
1HL= 100L
Dekaliter
1 DL= 10L
(abbr. HL)
(abbr. Dm)
Deci 1/10 Centi
1/100
Milli
1/1000
Meters
Decimeter
(Abbreviati
on is m)
Centimeter
1cm
Millimeter
1mm=
1dm=0.1m
0.01m
.001m
Centiliter
1cL
Millimeter
1mL=
0.01L
.001L
Liters
(L)
Deciliter
1dL=0.1L
(abbr. KL)
You fill this like the above
row!
Grams
(g)
You fill this like the above
row!
Homework Help!
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11) 1 mL = 0.001L (see previous slide!)
12) 5 cm = 50 mm
13) 10 mg = 0.01 g (1 mg = 0.001 g)
14) 39 m = 39000 mm
You figure out the rest!