Energy Losses and Efficiency
Machines lose energy through friction, deformation and wear, which is dissipated as heat. This means the power out of the machine is less than power in. The ratio of power out to power in is the efficiency η of the machine, and is a measure of the energy losses,
The velocity ratio of a machine is fixed by its dimensions, so it is the mechanical advantage that is reduced by the losses, that is
So in non-ideal machines, the mechanical advantage is always less than the velocity ratio by the product with the efficiency η. So a machine that includes losses such as friction, deformation and wear, will not be able to move as large a load as a corresponding ideal machine using the same input force.
The efficiency of a compound machine is the product of the efficiencies of the series of simple machines that form it,
Read more about this topic: Simple Machine
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