apes unit 6

im totally fine and everything is great wow i love junior year

photovoltaic cells

-SOLAR energy

-does not produce electricity on cloudy days

natural gas

-CH4 burns more completely

-CLEANER than other fuels

watts —> kW —→ kWh

-watts = unit for generating electricity

-1 kilowatt = 1,000 watts

-1megawatt = 1,000,000 watts

-1 kilowatt hour = 1 kilowatt x hour/time

annual exponential growth

Final Population (FP) = Initial Population (P) (1+r (rate))^Time (t)

percent change

New Value - Old Value/Old Value = x 100 =

percent calculations

Part/Whole x 100 = %

wind farms

-offshore wind farms produce 3x electricity due to increased wind currents

-best in open fields, birds can die

biomass

-burned in developing countries

-cheaper than extracting fossil fuels

-burning wood for cooking/heating

-needs effective VENTILATION

petroleum oil

-used in asphalt, DDT, polystyrene (Styrofoam), and nylon

-most used globally

biofuel

ex/ ethanol from corn requires a high energy investment

fracking

-pumping pressurized water with chemicals into boreholes to create cracks to release gas and oil

-fluids can escape and contaminate groundwater

nuclear energy

-non-renewable due to uranium

-no CO2 emissions

nuclear power plant accidents

-three mile island

-Chernobyl

-Japan

hydrogen fuel cell vehicles

-no carbon emissions

-uses hydrogen to generate electricity

coal —→ acid rain formation

3 types:

-peat

-lignite

-bituminous

-anthracite (highest grade coal)

major world fuel sources

-coal

-oil

-natural gas

CO-generation principle

heat first —→ steam for electricity

geothermal

-expensive

-needs electricity

-used in Iceland though

half-life math

-the time it takes for HALF of a sample to radioactively decay

-ex/ with a radioactivity level of 100 Curies and a half life of 50 years, what will the radioactivity level be in 200 years?\

100 50 25 13.5 6.25

→50 →50 →50 →50