The runner's achilles tendon stretch is 5mm.
What is Young's modulus?
Young's modulus (Y) is described by the following expression.
[tex]Y = \frac{F \times L}{ΔL \times A } [/tex]
where,
F=force exerted on the tendon
A=area
∆L=change in length (streching)
The force in this case is 8 times the weight of the runner
F=8×m×g
F=8×70×9.8
F=5488N
therefore,the change in length of the tendon is given by
[tex]Δ = \frac{F \times L}{ Y \times A } [/tex]
[tex]ΔL = \frac{5488 \times 0.15}{0.15 \times 10 {}^{10} \times 1.1 \times 10 {}^{ - 9} } [/tex]
ΔL=0.00498m
The runner's achilles tendon will stretch by 0.004989m which is approx.5mm
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