Answer:
The efficiency of a simple machine is defined as the ratio of useful work done by the machine ( output work) to the total work out into the machine ( input work).
Step-by-step explanation:
Efficiency
If a machine overcomes a load ' L ' and the distance travelled by the load is 'Ld' , the work done by the load is L× LD. It is also called output work or useful work.
Therefore,
![\boxed{Output \: work \: = L \: * \: Ld}]()
Likewise, The effort applied to overcome the load is 'E' and the distance covered by effort is 'Ed' , the work done by effort is E × Ed. It is also called input work.
Therefore,
![\boxed{Input \: work = E * Ed}]()
The efficiency of a simple machine is defined as the ratio of output work to the input work .
Therefore,
![\boxed{Efficiency ( η)= (outpt \: work)/(input \: work) * 100\%}]()
Efficiency is expressed in percentage. It is a ratio of two works. A machine is never 100% efficient. It is because no machine is friction free and due to friction, some of the input energy is wastes in the form of heat energy.
