Efficiency+by+Michaela+and+Jessica

Comparison of work input to work output. %Efficiency = Work output / Work input X 100
 * Work that comes out of a machine (work output) can never be greater than the work that go's into the machine (work input).
 * Work output is always less than the work input.
 * The closer work output is to work input, the more efficient the machine.
 * Efficiency can never be greater than a hundred percent,if there was no friction the effiency would be one hundred.
 * The operation of any machine always involves some frictioning.
 * Heat is created because of friction.