30 cm 4 cm - Bone -Muscle 100 (A) (B) FIGURE 1.12 (A) Weight held in hand. (B) A simplified drawing of (A). 40 cm 1.2 m 0.9 m FIGURE 1.7 Increased stability resulting from spreading the legs. F 1. Calculate the force required to topple a person of mass = 70 kg, standing with his feet spread 0.9 m apart as shown in (Fig. 1.7). Assume the person does not slide and the weight of the person is equally distributed on both feet. 2. 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 of the textbook. Note that under these conditions the lower part of the arm is no longer horizontal.