What is the function of a prism

The achilles tendon connects the muscles in your calf to the back of your foot. when you are sprinting, your achilles tendon alternately stretches, as you bring your weight down onto your forward foot, and contracts to push you off the ground. a 70 kg runner has an achilles tendon that is 15 cm long and has a cross-section area of 110 mm2 typical values for a person of this size. part a by how much will the runner's achilles tendon stretch if theforce on it is 8.0 times his weight? young's modulus for tendor is 0.15*1010n/m2. express your answer to two significant figures and include the appropriate units. part b what fraction of the tendon's length does this correspond.