Answer:
Sound waves. Anything that vibrates is producing sound; soundis simply a longitudinal wave passing through a medium via the vibration of particles in themedium. Consider a sound wavetraveling in air
15 because i did the math, had this assignment, and also watch a video
<span>The
thermal energy found in a piece of coal is lesser than in the thermal energy in
a newly opened coal mine. The newly opened coal mine requires a greater thermal
energy to really open it due to its solid structure. Whereas in a piece of
coal, it only requires a lesser amount of thermal energy to extract it.</span>
Actually, hydroelectric and coal-fired power plants produce electricity in a similar way. In both cases a power source is used to turn a propeller-like piece called a turbine, which then turns a metal shaft in an electric generator,which is the motor that produces electricity. A coal-fired power plant uses steam to turn the turbine blades; whereas a hydroelectric plant uses falling water to turn the turbine. The results are the same. :) <span>
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