Transcript Day-02-Thursday-27-August-2015-Metric-System

Day 2, Thursday, 27 August, 2015
The Metric System
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Physics and Science
The Metric System
Scientific Notation
Day 6, Tuesday, 31 August, 2010
Metric System
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Physics and Science
The Metric System
Scientific Notation
What is Physics?
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Physics (Greek: φύσις (phúsis),
"nature" and φυσικῆ (phusiké),
"knowledge of nature") is the branch of
science concerned with discovering and
characterizing universal laws that
govern matter, energy, space, and
time.
Limits of science
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Natural sciences deal only with what is
observable or testable.
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Science cannot go into matters of faith
Scientists and experiments are flawed. The
process (over time) is self correcting.
Difference between Art and
Science
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Science agrees on some main points
(theories). So progress may be judged.
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Freud turned Psychology into a science.
Art has no point of agreement. There is
no way to judge progress.
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Bach vs Beatles
Major branches of science
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Chemistry
Physics
Biology
Minor branches of science
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Places
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Relationships
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Geology, Oceanography, Meteorology,
Astronomy
Environmental Science
Special interests
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Psychology, Anthropology, Sociology, etc.
Metric System
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Metric System
International System of units (SI)
MKS
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Meter, Kilogram, Second
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CGS
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Centimeter, gram, second
Metric Units
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Units (multiples of ten)
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Base
Derived
Prefixes
Base Units
Length
Mass
Time
Amount
Temperature
Electrical current
Luminosity
Meter
Kilogram
Second
Mole
kelvin
ampere
Candela
Derived Units
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Electrical resistance
Frequency
Force
Energy
Power
Voltage
ohm
hertz
newton
joule
watt
volt
Scientific Notation
1.234 X
5
10
3 parts to a number in scientific
notation
1.
The Coefficient
2.
Times 10
3.
The Exponent
The Coefficient
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This is the actual number (in front)
It must have one digit before the
decimal point. So, it is between 1 and
10.
Drop all trailing zeros (unless they were
measured and therefore significant).
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If the number is negative (less than
zero)
Then the coefficient will be negative
-1.23
Times ten
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Every number in scientific notation has
“times ten” in the middle, written as
X 10
The Exponent
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The exponent is the exponent of the
“times ten”
11
X10
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It tells the number of tens columns the
decimal has been moved over.
The exponent may be positive, or
negative
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A positive exponent means the
number has zeros behind it and is big
(greater than one).
A negative exponent means the
number has zeros in front of and is
small (a fractional number between
zero and one).
Big Numbers
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Big numbers have trailing zeroes before
the decimal .
123,000,000,000.
Big numbers have positive exponents.
11
10
Small Numbers
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Small numbers (fractional numbers
between zero and one) have leading
zeroes after the decimal point.
.0000000000123
Small numbers have negative
exponents.
-11
10
Adding and Subtracting (poor
way)
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Put in decimal form
Perform the addition or subtraction
Convert back to Scientific Notation
The size of the number will be the
larger exponent (plus or minus one)
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1.23 X 1011
4.56 X 107
123,000,000,000.
45,600,000.
122954400000.
1.229544 X 1011
Adding and Subtracting (better way)
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Rewrite to get the same exponent
Add or subtract the coefficients
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1.23 X 1011
4.56 X 107
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12,300.00 x 107
4.56 x 107
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12,295.44 X 107 = 1.229544 X 1011
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An interesting insight
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When you add or subtract in scientific
notation the answer will often have the
same exponent as the larger number.
The answer’s exponent will never differ
from the larger number exponent by
more than  1.
Multiplying and Dividing
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Multiply or divide the Coefficients
normally
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Add exponents when multiplying
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Subtract exponents when dividing
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Multiplication
(2 X 105) (4 X 103)
Coefficients 2 X 4 = 8
Exponents 5 + 3 = 8
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Answer
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8 X 108
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Division
2 X 105
4 X 103
Coefficients
Exponents
2/4 = .5
5-3 = 2
Unformatted answer .5 X 102
Proper answer
5 X 101
Credits