Question

During an exercise a 70kg person does toe (or calf) raises exerting four times their body weight on their achilles tendon. This tendon is 25 cm long, has a cross sectional area of 80 mm2 and an elastic modulus of 1.5 GPa. How much does the exercise stretch the achilles tendon? 22 mm 1.3 mm 13 mm O 5.0 mm

Answer 1

m=70 kg F = 4mg = 4x70x9.8 Fo 2744 N t=0025 m, A = 80mm A = dox 10 m² , Y = 1.5 G Pa Y = 15x100 la Let the extension is oL. -YAL A.AL AL = FL DL - AY AL 3 2744 x 0.25 80x100x1.5x109 AL = 5.72 xto? TAL = 5 mm approx.