100 kg

The figure shows a person wearing weight boots and doing lower leg flexion/extension exercise in a sitting position to strengthen the quadriceps muscles and a simple mechanical model of his leg. W1 is the weight of the lower leg, W0 is the weight of the boot, the magnitude of the pulling force applied to the tibia by the quadriceps muscles through the FM patellar tendon, the magnitude of the reaction force acting on the FJ tibiofemoral joint. Point O is the center of the tibiofemoral joint, point A is the point where the patellar tendon attaches to the tibia, point B is the center of gravity of the lower leg, point C is the center of gravity of the weight boot. The distances between point O and points A, B and C were measured as a=13 cm, b=27 cm and c=36 cm, respectively. The angle that the long axis of the tibia makes with the horizontal is β=34°, the angle between the line of action of the quadriceps muscle strength and the long axis of the tibia is α=18°. Points O, A, B and C lie…

5. The figure below represents the anatomy of the lower limb when balanced on your toes and the body weight acts through the tibia. The Achilles Tendon makes an angle (0) of 8° with the vertical and for this foot x1 is 6.2 cm and x2 is 12.3 cm. Calf Muscle Tibia Achilles Tendon Calculate the tension (T) in the Achilles Tendon if a 70 kg man stands on the toes of both feet. Using the values in this example what is the mechanical advantage for this lever and describe what that means in terms of the efficiency of the lever.

The figure on the left, below, shows a non-uniform bent rod with a mass of 5 kg. Your job is to determine the location of the center of gravity of this rod. You design an experiment: you connect a pin and cable to the rod such that it safely stays in static equilibrium under a force P that you apply. Then, you apply forces between 0-100 N, and measure the tension force on the cable using a cable tension meter. The results of your experiment are shown in the figure, on the right. Using this experiment, calculate (approximately) the horizontal distance (x in the figure) between point A and the center of gravity G of the bent rod. B C O I 20 cm 20 cm 60° D 50 cm Tension measurement [N] 60 50 40 30 20 -10 0 10 real data estimated fit 20 30 40 ܐܐܝ 50 P[N] 60 70 80 90 100