Simple devices

Text and pictures introduce the wheel, a simple machine used primarily to make it easy to move heavy loads.

Text and pictures introduce the wedge, a simple machine placed between objects to split, tighten, or secure a hold.

Text and pictures introduce the screw, a simple machine used primarily as a fastening device.

Text and pictures introduce the pulley, a simple machine used primarily to lift heavy objects.

Text and pictures introduce the lever, a simple machine used to change force and motion.

Text and pictures introduce the inclined plane, a simple machine consisting of a slanted surface or ramp to make work easier.