High Power, Low Cost

fuels made from the remains of living things from long ago; they are burned for energy

• fossil fuels
• renewable resource
• high-altitude
• friction

a natural resource that is replaced at about the same rate as it is used

• fossil fuels
• renewable resource
• high-altitude
• tether

a machine with fan-like blades that turn

• exceed
• friction
• turbine
• convert

high above the ground or sea

• turbine
• fossil fuels
• renewable resource
• high-altitude

the number of miles something or someone travels in one hour

• mph
• exceed
• convert
• turbine

to be greater than something in quantity

• tether
• exceed
• convert
• friction

a force that resists motion; the force of resistance that one thing puts on another as a result of being in contact

• turbine
• fossil fuels
• friction
• renewable resource

to fasten something to an object with a rope or chain

• convert
• high-altitude
• mph
• tether

to change the nature or form of something

• convert
• friction
• exceed
• turbine

Synonym for "tether"

• unfasten
• fasten
• untie
• undo