3. Metric System
Since the 1960s the International
System of Units ("Système
International d'Unités" in French,
hence "SI") has been the
internationally recognized standard
metric system.
5. A standard set
of prefixes in
multiples of ten
may be used to
derive larger
and smaller
units.
Metric System
6. The Metric and
Customary Systems of
Measurement
In today’s global
environment, metric
measurements are
prominent in
workplaces,
consumer products,
and news reports.
7. Almost every other
country in the world
uses the metric system
of measurement.
Three nations have not officially adopted the International System of Units as
their primary or sole system of measurement: Burma, Liberia, and the
United States.
8. The European Union, Japan, and Korea have
passed legislation limiting international commerce
to products measured in metric units.
Countries by Date of Metrication
9. If the United States is to continue
to play a leading role in
international business, using
metric measurement is imperative
and U.S. workers at all levels must
be knowledgeable about the
Système Internationale (SI), the
international name for the metric
system.
The Metric and
Customary Systems of
Measurement
10. Cargo errors - The confusion
between pounds (mass) and
kilograms sometimes means that
aircrafts are overloaded. "the
shipper's weights had been in
kilograms, not pounds, and that,
as a result, the aircraft was more
than 30,000 pounds overweight".
Importance of
Conversion…
11. Importance of
Conversion…
Gimli Glider — In 1983 a
Boeing 767 jet ran out of fuel in
mid-flight because of two
mistakes in figuring the fuel
supply of Air Canada's first
aircraft to use metric
measurements.
12. Medical errors - Medical errors
in the US are sometimes
attributed to the confusion
between grains and grams. A
patient received phenobarbital 0.5
grams instead of 0.5 grains (0.03
grams) after the prescriber
misread the prescription.
Importance of
Conversion…
13. Mars Climate Orbiter — In 1999
NASA lost a $125 million Mars
orbiter because one engineering
team used metric units while
another used US customary units
for a calculation.
Importance of
Conversion…
14. Metric System
• One of the goals of the metric
system is to have a single unit
for any physical quantity.
15. • Another
important one
is not needing
conversion
factors when
making
calculations
with physical
quantities.
Metric System
16. • All lengths and distances are
measured in meters, or
thousandths of a meter
(millimeters), or thousands of
meters (kilometers), and so on.
Metric System
17. • There are not different units
with different conversion
factors, such as inches, feet,
yards, fathoms, rods, chains,
furlongs, miles, nautical miles,
leagues, etc.
Metric System
18. • Multiples and submultiples are
related to the fundamental unit by
factors of powers of ten, so that one
can convert by simply moving the
decimal place: 1.234 meters is 1234
millimeters, 0.001234 kilometers,
etc.
• The use of fractions, such as 2⁄7 of a
meter, is not prohibited, but uncommon,
as it is generally not necessary.
Metric System
19. • The US uses
the English
System of
measurement.
• Not even the
English use
the English
system
anymore.
Metric System
20. Metric System
• The rest of the world, especially
scientists, use the metric system, or
System International (SI).
• Since we are in the US, your lab
manual uses both systems.
• We need to be familiar and comfortable
using both systems.
• We also need to be able to convert units
from one system to another.
21. 1. Approximations: the kind you
can do easily in your head
2. Precise Equivalents: necessary
for exact measurements.
Levels of Conversion
There are two levels of conversion:
Commonly used conversions: pages 3-4
23. Rounding
• No…
• It is usually implied that the
greater number of digits more
precise.
• Not always
24. • Distance measurement is only
accurate to tenths of centimeters,
so a final answer should be no
than one decimal point.
Rounding
25. Rounding
• If the first digit to be dropped is
less than 5, leave the preceding
digit.
• If the digit is greater than 5,
increase the preceding digit by
one.
• Example: 6.74 = 6.7
• Example: 6.75 = 6.8
26. Problems
• Beginning on page 5
• Use the conversion charts on
pages 3 and 4
• Do problems part one # 1 A-G, #2
A-I, and part two #1 A-G, #2 A-I
27. Part One # 1 Problems
• A centimeters to inches
• 10 cm =______ inches
• 1 cm = 0.394 in
• 10 cm X 0.394 in = 3.94 in
• Rounded = 3.9 in
• B meters to feet
• 10 m = ______ ft
• 1 m = 3.281 ft
• 10 X 3.281 = 32.81 ft
• Rounded 32.8 ft
• C kilometers to miles
• 50 km = _____ mi
• 1 km = 0.621 mi
• 50 km X 0.621 mi = 31.05 mi…..31 mi
28. Part One # 1 Problems
• D liters to quarts
• 60 lt = ________ qts
• 1 lt = 1.057 qts
• 60 X 1.057 = 63.42….63.4 qts
• E grams to ounces
• 98 g = _______oz
• 1 g = 0.035 oz
• 98 X 0.035 = 3.43…….3.4 oz
• F kilograms to pounds
• 20 kg _____ lbs
• 1 kg = 2.205 lbs
• 20 X 2.205 = 44.1 lbs
• G Celsius to Fahrenheit
29. Part One # 1 Problems
• G Celsius to Fahrenheit
• This is a little different, there is a
formula to convert: (C° X 1.8) + 32
= F°
• 39° C = ______ °F
• (39 X 1.8) + 32 = 33.8° F
• 100° C = _____ °F
• (100 X 1.8) + 32 = 212° F
• 1° C = ______ F °
• (1 X 1.8) + 32 = 33.8° F
30. Part One Problems #2
• A inches to centimeters
• 8 in = _____ cm
• 1 in = 2.54 cm
• 8 X 2.54 = 20.32 cm…rounded 20.3 cm
• B feet to meters
• 6 ft = ____ m
• 1 ft = 0.305 m
• 6 X 0.305 m = 1.83 m…..1.8 m
• C yards to meters
• 12 yds = ______ m
• 1 yd = 0.914 m
• 12 X 0.914 = 10.94 m …… 11 m
31. Part One Problems #2
• D miles to kilometers
• 20 mi = ___ km
• 1 mi = 1.609 km
• 20 X 1.609 = 32.18….32.2 km
• E quarts to liters
• 12 qts = ____ lt
• 1 qt = .946 lt
• 12 X .946 = 11.352….11.4 lt
• F gallons to liters
• 5 gal = _____ lt
• 1 gal = 3.785 lt
• 5 X 3.785 = 18.9…19 lt
32. Part One Problems #2
• G ounces to grams
• 6 oz = _____ g
• 1 oz = 28.35 g
• 6 X 28.35 = 170.1 g
• H pounds to kilograms
• 20 lbs = ____ kg
• 1 lb = 0.454 kg
• 20 X 0.454 = 9.08….9.1 kg
33. Part One Problems #2
• I Fahrenheit to Celsius
• Another formula: (F° - 32) / 1.8 = C°
• 90° F = ____° C
• (90 – 32) / 1.8 = 56.2° C
• 15° F = ____° C
• (15-32) / 1.8 = -9.4° C
• 212° F = _____° C
• (212-32) / 1.8 = 100°C
