This was for a school project where my son needed to make a compound machine three simple machines. This one had an incline, a pulley, and a wheel-axle.
A compound machine is a machine composed of two or more simple machines. Common examples are bicycles, can openers and wheelbarrows. Simple machines change the magnitude or direction of a force without any motor.
Simple machines are generally easy to understand and work on simple principles. They include such things as levers, which grant mechanical advantage, and wedges, which redirect relative motion, and wheels of various sorts, from pulleys to bicycle gears. These, put together, form a compound machine.
One of the simpler and older compound machines is a wheelbarrow. The classic wheelbarrow consists of two levers – its handles, which give mechanical advantage in lifting their load. They also have a wheel, which translates forward motion into rotary motion, decreasing frictional resistance compared to dragging. Another simple example is a pair of scissors. This consists of two levers with a class one fulcrum, which is a fulcrum that changes the direction of motion.