1. Forces in the Forearm: A weightlifter is holding a 50.0-lb weight (equivalent to 222.4 N) with his forearm, as shown in the figure. His forearm is positioned at $eta$=60° with respect to his upper arm. The forearm is supported by a contraction of the biceps muscle, which causes a torque around the elbow. Assuming that the tension in the biceps acts along the vertical direction given by gravity, what tension must the muscle exert to hold the forearm at the position shown? What is the force on the elbow joint? Assume that the forearm's weight is negligible. Give your final answers in SI units. Figure 12.11 The forearm is rotated around the elbow ($E$) by a contraction of the biceps muscle, which causes tension $T_M$.
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- The weightlifter is holding a 50.0-lb weight, which is equivalent to 222.4 N (since 1 lb ≈ 4.448 N). - The forearm is positioned at an angle, but the specific angle (B-609) seems to be a typographical error. Typically, angles in these problems are given in Show more…
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