Bone CompressionTension problem

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Homework Help Overview

The discussion revolves around a problem involving the compression and tension of a bone, specifically focusing on the application of Young's modulus in both scenarios. The original poster presents a scenario where a bone experiences a decrease in length under compression and seeks to determine the corresponding stretch under tensile force.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • The original poster attempts to apply the formula for Young's modulus but notes the absence of cross-sectional area, leading to considerations of proportional relationships. They question whether the negative change in length under tension would simply be the opposite of the compression change.

Discussion Status

Participants are exploring the relationship between the two scenarios, with some clarifying that the force magnitude, initial length, and cross-sectional area remain constant. The original poster expresses relief upon realizing a simpler approach to relate the two situations through the Young's modulus values.

Contextual Notes

There is a noted lack of information regarding the cross-sectional area, which is central to applying the formula correctly. The discussion reflects uncertainty about the implications of this missing data on the problem-solving process.

shaka23h
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When subjected to a force of compression, the length of a bone (compression Young's modulus 9.4 x 109 N/m2, tensile Young's modulus 1.6 x 1010 N/m2) decreases by 3.7 x 10-5 m. When this same bone is subjected to a tensile force of the same magnitude, by how much does it stretch


Ok after carefully looking at this problem I realized that the formula that would apply here would be

F = Y (delta L/ L0 ) A

Where y = young's Modulus Delta L = change in length and A = cross sectional area. But after looking at this problem I realized that there is no cross sectional area given, therefore I'm thinking that it is just a proportional problem.

It seems like I'm making this problem a bit harder then it actually is. Perhaps I'm missing something important?

I know that Tensile force is opposite Compression but in this case the answer would not just be the negative change in length right?

Please help
 
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ya pleaseexplain even i did not understand
 
force magnitude, initial length and cross sectional area are the same both times. differs only Y and delta L.
 
ok I got it thanks :) just had to set Y1 delta L = Y2 (x) and solve for X. You see I knew I was thinking about this problem a bit too hard LOL.
 

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