# How Do You Define A Machine In Physics?

A machine is a device by which a small force applied at convenient point can be used to overcome a large force at some other point. Although the force overcome by a machine is many times greater than the input force, the energy or work output can never be greater than the input energy or work. In principle                Work input=Work output    In a machine, some energy is always wasted in overcoming frictional forces. In practice, therefore, the useful work done by a machine is always less the input work. The ratio of the useful work done by a machine and input work is called the efficiency of the machine. Usually, the ratio is expressed as a percentage, i.e.    Efficiency=Useful work done by the machine/Work done on the machine*100%    Thus in practice the efficiency of a machine is always less than 100 per cent.
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A machine is a device that allow a force applied at one point to be overcome by a resisting force at another point.
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A machine is device in which a small application of force at one end can be used to overcome a greater effort at the other end.
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A machine is adevice that overcome with a large resistive force by applying small force in convenient direction at conveniont point
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