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43 Cards in this Set
- Front
- Back
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How many miles in a km
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0.62mi = 1km
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How many square miles in an acre
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70m x 70m
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How much biomass can be grown on a square meter in a year
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1kg/m2
10tons/ha |
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How much thermal chemical energy is in a kg of biomass
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16 MJ/kg
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How much thermal chemical energy is in a kg of coal
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30 MJ/kg
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How much thermal chemical energy is in a kg of petroleum
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50 MJ/kg
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In a stndard (Rankine) combustion power plant for either coal/biomass/nuclear power, what fraction of the energy is converted into electricity
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30%
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How many liters are in a gallon
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3.78 liters = 1 gallon
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How much does a liter of water weigh
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1kg
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What is the density of air
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1.2 kg/m3
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How many joules are in a MJ
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10^6 J = 1 MJ
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How much power from the sun reaches earth (solar constant)
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1366 W/m^2
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How many calories of food does a typical person eat in a day
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2000 Kcal/day
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How many joules does a typical person eat in a day
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8.4 MJ/day
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How many joules are in a Btu
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1055 J = 1 Btu
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How many joules are in a calorie
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1 cal = 4.2 J
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What is the peak power to reach the surface of earth on a clear day
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950 W/m2
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What is the efficiency of solar photovoltaics today
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20%
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What is power flowing through a wind turbine
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P = (1/2)(pi)(r2)(v3)(air density)
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What is the maximum amt of power that can be extracted from wind through a turbine (Bentz limit)
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60%
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What is the world population
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6 billion
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What is the US population
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300 million
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What is the population of china
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1.3 billion
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What is the US GDP
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13 trillion
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What is the WDP
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60 trillion
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How much primary energy is used in the US
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100 EJ
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How much energy is used worldwide
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400EJ
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How many joules in a kWh
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1 kWh = 3.6 MJ
(1 W = 1 J/sec) |
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How many kWh does a 60 watt bulb use in 10 hours
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60W*10hr = 600 kW * hr = 0.6 kWh
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What is a typical price of electricity
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$0.05 kWh
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How many gallons are in a barrel
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31 gallons = 1 barrel
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How much power can be derived from water falling from a height h at a rate of x
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E = mgh
P = (m/t)gh P(electricity) = (0.9)(m/t)gh |
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How much energy does it take to raise the temperature of water 1 degree centigrade
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1 J
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Wat are the atomic masses of Carbon, Oxygen, Hydrogen
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12, 16, 1
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What is an EJ
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100*10^18 J
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What is a quad
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10^15 Btu
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How many Btus are in a therm
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1 therm - 10^5 Btu
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How many Joules are in a therm
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1 therm = 100 MJ
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How much does a therm cost
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$1.58
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What is the presidential budget
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$3.1 trillion
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How many acres of US cropland are there
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440 million acres
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What is the radius of the earth
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6,378 km
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How many GJ are in a toe
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Ton of oil equivalent
1 toe = 42 GJ |
