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What is one way we could make Earth's coal supply last longer?
Teach public energy conservation
Which of these is an advantage of hydroelectric energy?
A renewable energy source
What is a disadvantage of usings solar energy?
requires a high initial investment, must be in a location with high amounts of sun.
How many watts of light does a 23W CFL lightbulb generate? if it has a 10% energy efficiency?
2.3 W
A student spent 10 minutes cleaning her car with a 500W vacuum cleaner. How much energy, in joules, did the vacuum cleaner use?
300,000 J
What kind of energy is stored when you stretch a spring?
What are some disadvantages of hydrogen fuel cells?
Hydrogen fuel is expensive to produce and transport, the purification of hydrogen fuel emits large amounts of CO2
What are some disadvantages of oil extraction from tar sands?
compared with drilling, it affects a much larger area and obtains less oil
If you have oil in your car's engine, the parts that rub together in the engine get very hot. What does the oil do?
it decreases the force of friction.
Which process best shows the steps in refining crude oil?
oil rig-->pipeline-->tanker truck-->refinery
List one source of energy for generating electricity produces the least amount of carbon dioxide?
What are some disadvantages of using natural gas?
extraction through fracking can contaminate groundwater
How are wind power and hydroelectric power similar?
they both use turbines to produce electricity.
Which energy source contributes least to global warming?
solar or wind
Which energy conversion occurs when solar panels are used to make electricity?
light energy to electrical energy
What is a benefit of using fossil fuels?
convenience, cost
When a ball drops from the roof of a building, it speeds up as it falls. What energy transformation is happening?
gravitational potential energy to kinetic energy
What is a drawback of extraction using hydraulic fracturing?
contamination of underground water
How is biomass energy different from wind energy?
Biomass energy uses a turbine to produce electricity.
What describes how coal forms?
remains of ancient plants are compressed by sediments
Which of the following is an effect of the electric force? (think subatomic particles)
two positive charges repel each other
A ball falls from the top of a building. As it falls, its speed increases. Which type of energy is the ball gaining as it falls?
Kinetic energy
You replace a 100W incandescent lightbulb with a 22 W CFL bulb. If you leave your lights on 24 hours day, how much energy are you saving each day by replacing this bulb?
6,739,200J
What method can be used to extract natural gas?
hydraulic fracturing
Will the coal reserves last forever based on our fuel needs?
No