Question

<Assignment 9 Graded 2020 Problem 11.83 6 of 6 > A young girl sits at the edge of a dock by the bay, dipping her feet in the water. At the instant shown in the figure(Figure 1), she holds her lower leg stationary with her quadriceps muscle at an angle of 39° with respect to the horizontal. Part A Use the information given in the figure, plus the fact that her lower leg has a mass of 3.3 kg , to determine the magnitude of the force, Fo, exerted on the lower leg by the quadriceps. Express your answer using two significant figures. VALD OD ? Submit Request Answer < Return to Assignment Provide Feedback Figure < 1 of 1 > Knee joint yo 29° 12 cmx Lower leg

Answer 1

Given z m=3.349 13 cm 390 Since her leg is stationary there is no acceleration & thees Fro, This means net force is zero, and not torque acting on her leg is zero we koow, z = rf sino 22=0 • solving at point A, ZA To = 12m x Fx sin 29° - Chorizontal component uopositine torque falong+xanis) solving at point B, ZB= (0.12 m+ 0.23m) (3.3 X9.8) sinisio i i negative torne Caloorg-x-axis) so TA-TB = 0 mgeing → 0-12 m) x FQ x sin290- (0-35m) (3-3) 6-8) Sins 0.0582 Fq -8-8055 =0 ta - Fa = 8.8055 .0582 = 151.3565N > 0.0582 Hence, magnitude of the force to exested on the lower leg by the quadricepe is 151-3565N.