Work is defined as force times distance. If you move something over 2 meters, and you need a force of 15 N for doing that, you'll deliver 30 Joules of work.
the work a machine does is the work outputwhat it takes to do the work is the work input Sources; http://wiki.answers.com/Q/The_work_that_the_simple_machine_does_is_called_the_work#ixzz1XBOCqF6K
