Energy
The 2nd law of thermodynamics states that...
In energy transformations some energy is always lost to the universe as heat
what happens when there is an energy crisis
price goes up
Describe how hydroelectric systems are used to produce electricity
What is the biggest advantage to using nuclear power to generate electricity?
There is no air pollution, no CO2 is emitted
What mineral naturally occurring in bedrock leads to the formation of radon?
uranium
watt
What are two environmental benefits of using natural gas compared to coal?
- More energy dense [highest energy content]
- lowest carbon emission
describe the best place for a wind turbine
open plains, coastal areas, mountain passes, open ocean
If a materials half life is 50 years, how long will it take 100kg to decay to less than1kg?
350 years
what is the best way to reduce unnecessary energy waste? name one example
improve energy efficiency
- using energy efficient appliances
name a unit of energy
joule,BTU, calorie, US therm
Name 4 nonrenewable energy sources
oil, coal, natural gas, nuclear
Explain how photo-voltaic cells produce electricity
by using the suns energy to create a flow of electrons in a material such as silicon
What is the risk of radiation exposure to human health?
increased risk of thyroid cancer
what is an economically viable EROI
3:1
if an electric car uses 50,000W of energy in an hour, how many kW is that?
50 kW
What is the biggest environmental issue with fracking to extract natural gas?
Groundwater contamination
explain how hydrogen is used in hydrogen fuel cells to power vehicles and what is the byproduct of the reaction?
hydrogen and oxygen pass through a electrolyte membrane which creates and electrical current and therefore energy. Pure water is the byproduct
What process actually generates the electricity in nuclear power?
nuclear fission
explain passive solar vs active solar
passive solar: uses the placement of a building [south facing windows] to passively heat a home
Active solar: uses solar panels to collect sunlight and photovoltaic cells to convert the sun's energy into electricity
if an oven uses 3,000 W of energy per hour and is running for 10 hours, how many kWh is that ?
30 kWh
Explain how nonrenewable resource power plants use heat to generate electricity
Burn the "resource" to produce steam to turn electric turbines/generators
explain the drawbacks of wind power [2/4]
- requires a lot of open space
- relies on batteries to store electricity produced
- eye sore
- dependent on weather patterns, may be inconsistent
Nuclear power does not produce any air pollution, other than radiation what is an environmental concern with nuclear power?
Thermal pollution of water sources
what two uranium isotopes are most commonly used in nuclear power?
uranium 235 and 238