FIGURE 1.11 The elbow. 30 cm Bone Muscle 100° 4 cm 40 cm (a) FIGURE 1.12 (a) Weight held in hand. (b) A simplified drawing of (a). (b) position as a Class 3 lever, as shown in Fig. 1.13. The x- and y-axes are as shown in Fig 1 13 The direction of the reaction force F, shown is a guess. The exact the arm can support in the position 1-5. Calculate the force applied by the biceps and the reaction force (Fr) at the joint as a result of a 14-kg weight held in hand when the elbow is at (a) 160° and (b) 60°. Dimensions are as in Fig. 1.12. Assume that the upper part of the arm remains fixed as in Fig. 1.12 and use calculations from Exercise 1-3. Note that under these conditions the lower part of the arm is no longer horizontal. Consider agai 1. 12 Now lot tho