Wheel and axle

These were made of stone or clay and secured to the ground with a peg in the center, but required significant effort to turn.

[2] The oldest surviving example, which was found in Ur (modern day Iraq), dates to approximately 3100 BCE.

Depictions of wheeled wagons found on clay tablet pictographs at the Eanna district of Uruk, in the Sumerian civilization of Mesopotamia, are dated between 3700–3500 BCE.

Depictions of a wheeled vehicle appeared between 3500 and 3350 BCE in the Bronocice clay pot excavated in a Funnelbeaker culture settlement in southern Poland.

[11] In Roman Egypt, Hero of Alexandria identified the wheel and axle as one of the simple machines used to lift weights.

[12] This is thought to have been in the form of the windlass which consists of a crank or pulley connected to a cylindrical barrel that provides mechanical advantage to wind up a rope and lift a load such as a bucket from the well.

[13] The wheel and axle was identified as one of six simple machines by Renaissance scientists, drawing from Greek texts on technology.

[14] The simple machine called a wheel and axle refers to the assembly formed by two disks, or cylinders, of different diameters mounted so they rotate together around the same axis.

The friction between wheel and road is actually quite low, so even a small force exerted on the axle is sufficient.

The actual mechanical advantage (AMA) of a wheel and axle is calculated with the following formula: where Basic Machines and How They Work, United States.