Answer:
The process of producing electric energy or the amount of electric energy produced by transforming other forms of energy into electrical energy; commonly expressed in kilowatt-hours (kWh) or megawatt-hours (MWh). Electric power plant efficiency η is defined as the ratio between the useful electricity output from the generating unit, in a specific time, and the energy value of the energy source supplied to the unit in the same time period. For electricity generation based on steam turbines 65% of all prime energy is wasted as heat. The maximum theoretical energy efficiency is defined in more detail by the Rankine cycle. For modern practical systems this is about 40% but less for older generating plant. The efficiency falls still further if fuels with lower energy content such as biomass are used to supply the plant. The economics of power generation based on reciprocating engines depends to a large extent on the use to which the engine is to be put. The cheapest engines available are small petrol-driven engines based on car engines, which are manufactured in large numbers each year.
Explanation:
the pitch which you hear will be greater than 300 Hz since the sound source is approaching you. But once stopped, the pitch will be 300 Hz exactly. So the pitch must be gradually decreasing from above 300 Hz to 300 Hz during the slowing down process.
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Force is a vector, A. Magnitude and Direction.
The melting of polar ice is one effect of the greenhouse effect, or also global warming.
The greenhouse effect, as defined by Merriam-Webster, is "the <span>warming of the surface and lower atmosphere of a planet (as Earth or Venus) that is caused by conversion of solar radiation into heat in a process involving selective transmission of short wave solar radiation by the atmosphere, its absorption by the planet's surface, and reradiation as infrared which is absorbed and partly reradiated back to the surface by atmospheric gases".
In short, "</span>the warming of the surface and lower atmosphere of a planet".