Simple Machines
Simple machines have existed for a long time, most of them for thousands of years. They are the building block for every machine that we used today. Even so, we still use many of them either on their own or in combination with one or two other simple machines. When simple machines are combined, we call them compound machines.
Simple machines DO NOT change the amount of work done. They DO, however, change the amount of force required to do work and the distance over which work is done. So we say: force x distance = work or with SI units newtons x meters = joules Joule is the SI unit for work. One joule is the amount of work done when one newton of force is exerted over one meter. So, think how much work you have done when you move about 1/4 of a pound a little farther than three feet and you will be getting pretty close. |