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Instructor: ENV Jim Leidel
SEB 93 Mondays 6-9PM
Only 13 Classes
Notes....
www.oakland.edu/energy You are not responsible to commit all of the following to memory. I want to expose you to a wide range of science, engineering, and energy information. You will be expected to have some basic ability to perform calculations, understand units, and identify and solve some energy problems. No worries !!!
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Stupid Math Tricks
Math Prerequisites Ex. 1 BTU (British Thermal Unit) is the amount of energy required to raise the temperature of one pound of water by one degree Fahrenheit How many BTUs in a gallon of gas? 125,000 BTU/gal
Stupid Math Tricks, cont.
How many BTUs does the U.S. use in a year? 100,000,000,000,000,000 BTU / year = 100 Quadrillion BTU = 100 x 1015 BTU
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Scientific Notation
125,000 = 1.25 x 105 100,000,000,000,000,000 = 1 x 1017 0.0032 = 3.2 x 10-3 On calculator, type:
1 . 2 5 EE 5 1 EE 1 7 3 . 2 EE 3
Note that 106 is typed 1 EE 6 (it is 1 x 106)
Prefixes useful with the metric system
kilo (k) = 103 (thousand) mega (M) = 106 (million) giga (G) = 109 (billion) tera (T) = 1012 (trillion) peta (P) = 1015 (quadrillion) exa (E) = 1018 Ex. 12 Mg = 12 x 106 g
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Stupid Math Tricks, cont.
Easy Example:
1 gallon = 3.785 liters 20 gal = ? liters 20 gal x 3.785 l/1gal = 75.7 l
Harder Example
How many Pg is 6 x 109 tons?
6 x 109 tons x 2000 lbs / 1 ton x 2.2 kg / 1 lb x 1000 g / 1 kg x 1 Pg / 1015 g
= 26.5 Pg
Mathematical Basis for Energy and Power
Need to define the quantities used to describe energy use.
Velocity, acceleration, mass, force, work, energy and power Also need to understand the metric units that we should be using and the alternate units that we will commonly see
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Quantity
Velocity
(= dist. time)
Metric Unit Alternate (m-kg-s) system Units
m
m
s
s2
= Acceleration v2 - v1 time
ft , miles s hr ft , etc. s2
g, slug lbf foot-pound kcal, BTU, kW-hr, ft-lb horsepower,
btu hr
Mass Force Work
(= mass accel.) (= force dist.)
Energy = Time
N J J W
Energy (= work) Power
(kg m s ) (kg m s ) (kg m s ) (J s ) (kg m s )
2
kg
2
2
2
2
2
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A Special Note on the Kilowatt Hour
1 kW = 1000 W This is a unit of power, 1 kW = 1000 J/s Since power = energy/time, energy=power x time Take the kW and multiply by the time, in hours, and you get a unit of energy
kWh = kw h 1000 J h s
(
)
As goofy as this is, it happens to be a unit of energy that is more useful than the joule (very small).
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Conservation of Energy
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animation
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ELECTRIC POWER NAT. GAS
RESIDENTAIL COMMERCIAL
COAL
INDUSTRIAL
PETROLEUM
TRANSPORTATION
source: Scientific American
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2010 - 2030
2040 - 2060
2070 - 2090
ARTIC SEA ICE is projected to shrivel.
Maps show September sea ice for three future periods.
source: Scientific American
1979-1990
1991-2002
2003
North polar ice concentrations, minim...