Fr Fm FIGURE 1.13 Lever representation of Fig. 1.12. W 90 Fm 7 cm 5.56 cm FIGURE 1.15 Walking on an injured hip. W 10 cm W 3. Consider the situation when the arm in Fig. 1.13 of the textbook supports two 14-kg weights, one held by the hand as in Fig. 1.13 and the other supported in the middle of the arm (20 cm from the fulcrum). Calculate the force of the biceps muscle and the reaction force. 4. Suppose that the biceps in Fig. 1.13 of the textbook contracts 2 cm. What is the upward displacement of the weight? Suppose that the muscle contraction is uniform in time and occurs in an interval of 0.5 sec. Compute the velocity of the point of attachment of the tendon to the bone and the velocity of the weight. Compare the ratio of the velocities to the mechanical advantage. 5. Calculate the forces in the limping situation shown in Fig. 1.15 of the textbook. At what angle does the force FR act?