A Basketball hoop whose height is adjustable is shown. The supporting post ABCD weighs 100 lb with center of gravity at point C, and the backboard-hoop assembly weighs 60 lb with center of gravity at point G. The height of the rim is adjustable by means of the screw and hand crank IJ, where the screw is vertical. If a person with 180 lb weight hangs on the rim.
a) Determine the support reactions at D.
b) Determine the forces supported by all members. (forces on every two-force member and all forces on every joint).
c) If the person is in motion (swing or jumping) on the rim, do the support forces at D be the same? Greater or less? Why?