We analyzed the biceps muscle example with the angle between forearm and upper arm set at 90º. Using the same numbers as in Example 9.4, find the force exerted by the biceps muscle when the angle is 120º and the forearm is in a downward position. Example 9.4: Muscles Exert Bigger Forces Than You Might Think Calculate the force the biceps muscle must exert to hold the forearm and its load as shown in ?Figure 9.27?, and compare this force with the weight of the forearm plus its load. You may take the data in the figure to be accurate to three significant figures.
Solution 31PE Step-by-step solution Step 1 of 2 Refer to the figure 9.27 provided in the text book. From the free body diagram refer to the figure 9.27 (b) provided in the text book. Since example 9.4 angles between biceps and forearm is and here angle between biceps and forearm is , due to this position of line joining force is change like a inclined plane.