Suppose the biceps were surgically reattached three centimetersfarther toward the person's hand. If the same bowling ball wereagain held in the person's hand, how would the force required forthe biceps be affected? Explain? (Select all that apply.) It wouldrequire less force because of the larger distance between the elbowand the location where the force from the biceps acts. It wouldrequire more force because the force is less nearly perpendicularto the moment arm. It would require more force because of thelarger distance between the elbow and the location where the forcefrom the biceps acts. It would require more force because the forceacts closer to the heavy bowling ball. It would require less forcebecause the torque for each newton of force from the biceps isgreater. PRACTICE IT Use the worked example above to help you solvethis problem. A W = 52.8 N (11.9 lb) weight is held in a person'shand with the forearm horizontal, as shown in the figure. Thebiceps muscle is attached d = 0.03039 m from the joint, and theweight is l = 0.353 m from the joint. Find the upward force vectorF exerted by the biceps on the forearm (the ulna) and the downwardforce vector R exerted by the humerus on the forearm, acting at thejoint. Neglect the weight of the forearm. F = N R = N EXERCISEHINTS: GETTING STARTED | I'M STUCK! Use the values from PRACTICE ITto help you work this exercise. Suppose you wanted to limit theforce acting on your joint to a maximum value of 8.13 102 N. (a)Under these circumstances, what maximum weight would you attempt tolift? N (b) What force would your biceps apply while lifting thisweight? N
