Efficiency+by+Brent

=Efficiency= Efficiency- Comparison of work input to work output.

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 * Machines make work easier
 * Machines can't be 100% efficient
 * Machines are used to overcome friction
 * The closer work output to work input the more efficient the machine is
 * The work output can never be greater than the work input

work output/work input Using a lever(incline plane)to lift the lid of the paint. Using a lever to pry a nail out of a piece of wood. Using a pully to lift a heavy objects. IPC Textbook
 * Joules