Metric System Measurements

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The Metric System

• ---The Universal Language of Measurement---
• Metric System scientists engineers use this
  language to communicate
• The metric system is often referred to as the
  International System (SI) of Units
• The metric system is based on the number 10 and
  multiples of 10.

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Metric Quantities

• We will encounter a number of (base) metric
  quantities through the course of this class.
• For now we will just focus on two
• Length
• Mass

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LengthThe distance between two points

• Meter (m) the basic unit of length in the
  metric system
• If it is not appropriate to measure something in
  meters we can use metric prefixes to describe
  quantities that are larger or smaller than a
  meter.
• Example if something is smaller we can use the
  centimeter
• Centimeter (cm) one hundredth of a meter
• 1 cm 1/100 m 0.01 m
• 100 cm 1 m
• Example if something is bigger we can use the
  kilometer
• Kilometer one thousand meters
• 1 km 1000m
• 1 m 1/1000 km

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Massa measure of the amount of matter in an
object

• Kilogram (kg) the basic unit of mass in the SI
  system
• Example if something is smaller we can use the
  gram (which is at the base of the scale, but is
  not the base unit of mass).
• Gram (g) one thousandth of a kilogram
• 1 g 1/1000 kg 0.001 kg
• 1000 g 1 kg
• Example if something is smaller still, then we
  can use a different prefix.
• Milligram (mg) one thousandth of a gram
• 1 mg 1/1000 g 0.001 g
• 1000 mg 1 g

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Metric Prefixes

• The metric prefixes all have a mathematical
  meaning. If you know the meaning of each prefix
  then it is VERY easy to convert from one unit to
  the other.
• Many of you have memorized some mnemonic for the
  metric prefixes (King Henry)
• FORGET THIS IT IS CRAP!
• Memorizing this does NOT mean that you know it,
  understand it, and can work with it.
• Actually, students who use this are often the
  ones that make the most mistakes.

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Metric Prefixes
Prefix Symbol Meaning Meaning
mega M 1000000 106 million
kilo- k 1000 thousand
hecto- h 200 hundred
deka- da 10 ten
-Base Unit- ----- 1
deci- d 0.1 tenth
centi- c 0.01 hundredth
milli- m 0.001 thousandth
micro µ 0.000001 10-6 millionth
nano n 0.000000001 10-9 billionth
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Metric Prefixes(same info in a different manner)
nano (n) 10-9 micro (µ) 10-6 milli(m) .001 1/1000 centi(c) .01 1/100 deci(d) .1 1/10 Base Unit 1 deka(da) 10 hecto(h) 100 kilo(k) 1000 Mega(M) 106
Example Convert 25cm to meters using dimensional
analysis.
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Solution
Convert 25cm to meters using dimensional analysis.
Set up a conversion fraction so that the units
that you have will cancel out.
Put the appropriate values in the fraction and do
the math.
Youll get the right answer every time without
worrying, oh, do I move the decimal to the right
or to the left. JUST DO THE MATH!!!!!
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Know the METRIC SYSTEM and use DIMENSIONAL
ANALYSISits easy! Trust me, this class will
be hard enoughdont make it worse.