Tension and compression forces on a femur bone

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The discussion focuses on calculating tension and compression forces on a femur bone, specifically addressing the need for clarity in stress calculations expressed in N/m^2. Participants highlight the incorrect approach of equating axial stress with bending stress, emphasizing that each should be calculated using their respective equations. There is a mention of the appropriate use of units, noting that N*mm^-2 is acceptable as MPa if tracked correctly. Additionally, the final answer provided lacks units, which is a critical oversight. Accurate calculations and proper unit usage are essential for understanding the forces acting on the femur.
mishelhad
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Summary:: Hello all,
I need help with this question, ill attach the equations i managed to solve.
How do i continue from there?

Screenshot_20210617-003639_Samsung Notes.jpg
Screenshot_20210617-003639_Samsung Notes.jpg
IMG-20210616-WA0024.jpg
 
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The stress should be expressed as N/m^2.

I have no idea how you determined the moment, but it certainly is not determined by the equation that you employed. It should be the force times the moment arm.
 
Looks like they found the axial stress and set it equal to the bending stress, which is incorrect. They should each be solved for by their respective equations.

I don't think there's anything inherently wrong with N*mm^-2, which is MPa, as long as the units are properly tracked. That said, the final answer doesn't even have any units with it.
 
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