Renewable vs. Nonrenewable
What type of energy resource is naturally replenished?
Renewable energy
What energy source do photovoltaic (PV) panels use?
Sunlight
Hydroelectric power uses moving water to spin what device?
A turbine
What renewable energy source uses the movement of ocean tides?
Tidal energy
What is a constraint in engineering design?
A limit or requirement the design must work within
Which fossil fuel is composed mostly of methane?
Natural gas
What device converts the rotation of a wind turbine into electrical energy?
Generator
What renewable resource uses heat from inside Earth?
Geothermal energy
Nuclear power plants release energy through what process?
Nuclear fission
What is the factor intentionally changed during an experiment called?
Independent variable
Name three nonrenewable energy resources.
Coal, oil, and natural gas (nuclear/uranium may also be accepted)
What location condition is especially important for wind energy?
Strong, consistent wind
Biomass energy comes from what type of material?
Organic material
What is one advantage of tidal energy?
Tides are predictable.
What is the factor measured as a result of a change called?
Dependent variable
Why are fossil fuels considered nonrenewable?
They form over extremely long periods and are used faster than they are replaced.
Why can solar and wind energy benefit from energy storage?
Storage saves energy for times when sunlight or wind is unavailable.
What is one limitation of geothermal energy?
It depends strongly on suitable underground geology/location.
What is one major limitation of tidal energy?
It is highly location-dependent.
Why should engineers change only one independent variable at a time during a fair test?
So they can determine which change caused the measured result.
What is one major advantage renewable resources have over fossil fuels?
They are naturally replenished and generally reduce dependence on finite fuels.
A student changes wind-turbine blade angle and measures voltage. What is the independent variable?
Blade angle
Describe the basic energy transformation in a hydroelectric system.
Moving/kinetic water → mechanical turbine motion → electrical energy
Why might engineers compare several energy sources before choosing one for a community?
Each source has different costs, environmental impacts, reliability, and location requirements.
Blade angles of 20° and 35° average 1.8 V and 2.4 V. Which design performed better, and what evidence supports the answer?
35° performed better because it produced the higher average voltage: 2.4 V versus 1.8 V.