The tension in the Achilles tendon will cause it to stretch. If the Achilles tendon is \(15 \mathrm{~cm}\) long and has a cross-section area of \(110 \mathrm{~mm}^{2}\), by how much will it stretch under this force?

A. \(0.2 \mathrm{~mm}\)

B. \(0.8 \mathrm{~mm}\)

C. \(2.3 \mathrm{~mm}\)

D. \(5.2 \mathrm{~mm}\)

When you stand on your tiptoes, your feet pivot about your ankle. As shown in Figure P8.63, the forces on your foot are an upward force on your toes from the floor, a downward force on your ankle from the lower leg bone, and an upward force on the heel of your foot from your Achilles tendon. Suppose a \(60 \mathrm{~kg}\) woman stands on tiptoes with the sole of her foot making a \(25^{\circ}\) angle with the floor. Assume that each foot supports half her weight.

Transcribed Image Text:

Achilles tendon. Ankle pivot 15 cm 20 cm FIGURE P8.63