When you stand on your tiptoes, your feet pivot about your ankle. As shown in the figure, 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 61 woman stands on tiptoes with the sole of her foot making a 25 angle with the floor. Assume that each foot supports half her weight.

Question

Sorry I can't add a picture to this b/c cramster doesn't have my book but....
From the toe to the ankle pivot is 15cm and from the toe to the Achillies tendon it is 20cm.

a)What upward force does the Achilles tendon exert on the heel of her foot N?
b)The tension in the Achilles tendon will cause it to stretch. If the Achilles tendon is 15 long and has a cross-section area of 110 , by how much will it stretch under this force?

Answer 1

Many of your numbers require dimensions. For example, what do you mean by "a 61 woman"?

Answer 2

883N

Answer 3

927