Simple Machines

Levers, pulleys, and inclined planes — making work easier

Simple machines are devices that make work easier by changing the force needed or the direction of force. There are six types: lever (a rigid bar pivoting on a fulcrum), pulley (a wheel with a rope), inclined plane (a ramp), wheel and axle (a large and small wheel together), wedge (two inclined planes), and screw (an inclined plane wrapped in a spiral). Mechanical advantage (MA) tells you how much a machine multiplies your force. MA > 1 means less force required (but more distance traveled). Work = Force × Distance; simple machines cannot create energy, they only redistribute it. W_in = W_out (in an ideal machine without friction).