The Hooke’s Law Apparatus is used to demonstrate that the relationship between the extension on a spring is proportional to the load applied to it. The complete apparatus has a 15cm adjustable scale, marked in millimeters, to mitigate parallax error. The scale is mounted on sturdy 30cm support rod and a wooden base. A hook supporting a coiled spring with a 10g mass hanger and indicator is attached to rod. Nine additional 10g slotted masses are included, for a total of 100g.