College Physics with MasteringPhysics 7th Edition by Jerry Wilson,Anthony Buffa,Bo Lou

Exercise 20

In Figure 8.4b, determine the force exerted by the bicep muscle, assuming that the hand is holding a ball with a mass of 5.00 kg. Assume that the mass of the forearm is 8.50 kg with its center of mass located 20.0 cm away from the elbow joint (the black dot in the figure). Assume also that the center of mass of the ball in the hand is 30.0 cm away from the elbow joint. (The muscle contact is 4.00 cm from the elbow joint; Example 8.2.)