Atwood's Machine

The nine foot high Atwood's Machine consists of a vertically mounted wooden plank that supports a light, essentially frictionless pulley. A light cord passing around the pulley is provided with small hooks which may be used to support steel weights of equal mass. The units of the scale are 0.1 meters per division.

A smaller version (about 2-3 feet high) sits on a lab bench--preferred if the room is small or already filled with stuff.