contestada

The legs of a weight lifter must ultimately support the weights he has lifted. A human tibia (shinbone) has a circular cross section of approximately 3.6 cm outer diameter and 2.30 cm inner diameter. (The hollow portion contains marrow.)If a 90.0 kg lifter stands on both legs, what is the heaviest weight he can lift without breaking his legs, assuming that the breaking stress of the bone is 150 MPa ?

Respuesta :

boffeemadrid

Answer:

249003822308.05008 N

Explanation:

F = Force

[tex]\sigma[/tex] = Breaking stress of bone = 150 MPa

[tex]d_2[/tex] = Outer diameter = 3.6 cm

[tex]d_1[/tex] = Inner diameter = 2.3 cm

Area of the bone is assumed to be a hollow cylinder

[tex]A=\dfrac{\pi}{4}(d_2^2-d_1^2)[/tex]

Stress is given by

[tex]\sigma=\dfrac{F}{A}\\\Rightarrow F=\sigma A\\\Rightarrow F=\dfrac{150\times 10^6}{\dfrac{\pi}{4}(0.036^2-0.023^2)}\\\Rightarrow F=249003822308.05008\ N[/tex]

The maximum weight the person can lift without breaking his legs is 249003822308.05008 N

Otras preguntas