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 prefer to 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—such as computers, cranes, and cars—are compound, or complex, machines. They combine more than one simple machine.
Simple machines are so common that you may overlook how much you rely on them, but without them, you’d find it hard—if not impossible—to get through a day.
