Which is easier: lifting a piano ten feet up in the air or pushing it up a ramp until it is ten feet from the ground?
Most people would rather push the piano up the ramp.
Ramps, also called inclined planes, are simple machines. Simple machines are devices that make work easier. Levers, wheels, screws, wedges, and pulleys are also simple machines. Other machines are compound, or complex, machines. These combine more than one simple machine and include computers, cranes, and cars.
Simple machines are so common that you may not see how much you rely on them. But without them, you would find it hard, if not impossible, to get through a day.
