How do I calculate the axial deformation of a member given force and dimensions?

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To calculate the axial deformation of a member under a given force and dimensions, the elongation equation e = (Force * Length)/(Area * Young's Modulus) is used. The discussion revolves around the distribution of force among the columns, with a specific focus on whether the force P is shared equally or if it affects only the outer columns. Clarification is provided that when the gap is just closed, there is no force on the central pillar, emphasizing the importance of understanding bending moments and beam deflection in this context. The conversation highlights a misunderstanding regarding the rigidity of the beam, ultimately confirming that it does not bend. Accurate interpretation of the problem is crucial for applying the elongation equation correctly.
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---Quote---
*1. Homework Statement *

http://postimg.org/image/yrbu7a0vb/

*2. Homework Equations *

e(elongation of a member) = (Force * Length)/(Area * Young's Modulus)


*3. The Attempt at a Solution *


Is the force P distributed so that the force on each bar is P/3 so that F2 would be (14/3)?


How do I use that value and the elongation equation to find the width of the gap?
I'm not sure what the relationship should be


thanks
 
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In (a), the centre column just avoids contact with the beam, leaving the two outer columns to support the entire force P.
 
princejan7 said:
Is the force P distributed so that the force on each bar is P/3 so that F2 would be (14/3)?
In part a)? No. When the gap is only just closed, there is not yet any force on the central pillar.
This is a question about bending moments and beam deflection. I don't see where elongation comes in before part b).
 
haruspex said:
This is a question about bending moments and beam deflection.
I don't think it is. I read it as the rigid beam does not bend.
 
NascentOxygen said:
I don't think it is. I read it as the rigid beam does not bend.
You're right - sorry. I completely misread it.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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