Chapter 12, Problem 20P

A bowler holds a bowling ball (M = 7.2 kg) in the palm of his hand (Fig. 12-37). His upper arm is vertical; his lower arm (1.8 kg) is horizontal. What is the magnitude of (a) the force of the biceps muscle on the lower arm and (b) the force between the bony structures at the elbow contact point?

Figure 12-37 Problem 20.