II. Apparatus
Rotational Apparatus (pictured above). Be sure that it has the following:
Hanging mass with string (C).
Crossbar with counter-weight (A,B).
Spring (G).
(Could use a photogate to count by attaching a flag to top of B.)String to go from mass (C) over pulley (E).
Clip to attach string to mass C.
Weight hanger (could be replaced with Vernier force sensor).
Mass sets for weight hanger.
Scale (Balance).
Stopwatch.