Calculating amount of compression a bone can withstand

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To calculate the amount of compression a bone can withstand, the stress equation (stress = elastic modulus x strain) is essential. The Young's modulus for bone is approximately 18 x 10^9 Pa, and it can endure a maximum stress of 160 x 10^6 Pa before failure. The discussion highlights the importance of understanding the relationship between stress, strain, and the change in length of the bone. Participants emphasize the need to carry units through calculations to avoid errors. Ultimately, recognizing that stress is defined as force per area simplifies the problem-solving process.
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Please I need help with this question. I know I have to use the stress = elastic modulus x strain equation, but i do not know how to apply it to this particular problem.


A Bone has a young's modulus of about 18 x 10^9 Pa. Under compression, it can withstand a stress of about 160 x 10^6 Pa before breaking. Assume that a femur (thighbone) is 0.50 m long, and calculate the amount of compression this bone can withstand before breaking.
 
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Hi sruthis, welcome to PF. In this problem, what is the elastic modulus? What is the stress? How is strain related to change in length? You have the right equation, now you just need to apply it correctly. Try to carry the units along with the numbers to avoid making an error.
 
I think I need to somehow use the equation F/A = Y(change in L/Linitial) and solve for Linitial, and i guess plug that value into the stress equation? but i do not know how to find A, and I am not sure if I have the right idea.
 
You're already given the stress, you don't need to find it by dividing force by area.
 
ohh. thank you so much. i completely did not realize that F/A was the stress. Thank you thank you.
 

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