Chapter 5, Problem 7P

|| BIO Muscles and tendons. Muscles are attached to bones by means of tendons. The maximum force that a muscle can exert is directly proportional to its cross-sectional area A at the widest point. We can express this relationship mathematically as F_max = σA, where σ (sigma) is a proportionality constant. Surprisingly, σ is about the same for the muscles of all animals and has the numerical value of 3.0 × 10⁵ in SI units. The gastrocnemius muscle, in the back of the leg, has two portions, known as the medial and lateral heads. Assume that they attach to the Achilles tendon as shown in Figure 5.41 The cross-sectional area of each of these two muscles is typically [&30 cm² for many adults. What is the maximum tension they can produce in the Achilles tendon?

Figure 5.41

Problem 7.