The patella P located in the human knee joint is subjected to tendon forces T1 and T2 and a force F exerted on the patella by the femoral articular A. If the directions of these forces are estimated from an X-ray as shown, determine the magnitudes of T1 and F when the tendon force T2 = 6 lb.. The forces are concurrent at point O.
A continuous of total length 4 m is wrapped around the small frictionless pulleys at A, B, C, and D. If the stiffness of each spring is k = 500 N/m and each spring is stretched 300 mm, determine the mass m of each block. Neglect the weight of the pulleys and cords. The springs are unstretched when d = 2 m.