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By what amount does the 52-cm-long femur of an 73 kg runner compress at this moment? The cross-section area of the bone of the femur can be
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By what amount does the 52-cm-long femur of an 73 kg runner compress at this moment? The cross-section area of the bone of the femur can be taken as 5.2×10−4m2 and its Young’s modulus is 1.6×1010N/m2.
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2021-09-05T02:28:55+00:00
2021-09-05T02:28:55+00:00 1 Answers
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Answer:
4.55×10^-5m
Explanation:
Young modulus of the material is equal to the ratio of the tensile stress to tensile strain of the elastic material.
Young modulus = Tensile stress/Tensile strain
Tensile stress = Force/cross sectional area
Give mass = 73kg
Force = mg = 73×10 = 730N
Cross sectional area = 5.2×10^-4m²
Tensile stress = 730/5.2×10^-4
Tensile stress = 1.4×10^6N/m
Strain = extension/original length
Given original length = 52cm = 0.52m
Tensile strain = extension(e)/0.52
Substituting the values given into the young modulus formula we have;
1.6×10^10 = 1.4×10^6/{e/0.52}
1.6×10^10 = 1.4×10^6×0.52/e
e = 1.4×10^6×0.52/1.6×10^10
e = 7.28×10^5/1.6×10^10
e = 4.55×10^-5m
This shows that the femur compresses by 4.55×10^-5m