Power is defined as the rate of energy transferred (and since work done = energy transferred, we can also state that power is the rate of doing work)
P = E/t or P = W/t Power is measured in watts (W). 1 watt = 1 joule/second Deriving P = Fv Power = W/t but W = Fd So P = Fd/t but v = d/t therefore, P = Fv Efficiency Whenever an energy transfer takes place we often find that not all of the input energy is transferred into the desired energy output. Often there is wasted energy (usually in the form of heat dissipated into the surroundings!). The efficiency of a system is defined as the percentage of the total input energy that is transferred into useful output energy: Efficiency = useful output energy / total input energy x 100% Comments are closed.
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