A small lab scale has a rigid L-shaped frame ABC consisting of a horizontal arm AB (length b = 30 cm) and a vertical arm BC (length c = 20 cm) pivoted at point B. The pivot is attached to the outer...

A small lab scale has a rigid L-shaped frame ABC consisting of a horizontal arm AB (length b = 30 cm) and a vertical arm BC (length c = 20 cm)

pivoted at point B. The pivot is attached to the outer frame BCD that stands on a laboratory bench. The position of the pointer at C is controlled by two parallel springs, each having a spring constant k = 3650 N/m, that are attached to a threaded rod. The pitch of the threads is p = 1.5 mm. If the weight is 65 N, how many revolutions of the nut are required to bring the pointer back to the mark?