Young's modulus of a hanging wire

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The discussion focuses on calculating Young's modulus for a titanium alloy wire subjected to a load. The wire, with a diameter of 0.5 cm and an initial length of 6 m, stretches 1.44 cm under a 60 kg mass. The formula used for Young's modulus is Y = (F/A) / (ΔL/L), where stress and strain are calculated based on the given dimensions and load. There are indications of arithmetic errors and unit discrepancies in the calculations presented. The thread also touches on determining interatomic bond stiffness related to the macro property of Young's modulus.
Westin
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Homework Statement


A hanging wire made of an alloy of titanium with diameter 0.5cm is initially 6m long. When a 60kg mass is hung from it, the wire stretches an amount 1.44cm. A mole of titanium has a mass of 48g, and its density is 4.54g[PLAIN]https://s3.lite.msu.edu/adm/jsMath/fonts/cmmi10/alpha/144/char3D.pngcm3.

Based on these experimental measurements, what is Young's modulus for this alloy of titanium?

Y=


As you've done before, from the mass of one mole and the density you can find the length of the interatomic bond (diameter of one atom). This is 2.60×10-10m for titanium. The micro quantity ks[PLAIN]https://s3.lite.msu.edu/adm/jsMath/fonts/cmmi10/alpha/100/char3B.pngi (the stiffness of one interatomic bond) can be related to the macro property Y. Determine the interatomic spring stiffness:

ks[PLAIN]https://s3.lite.msu.edu/adm/jsMath/fonts/cmmi10/alpha/100/char3B.pngi =

Homework Equations

Y=(FT/A) / (ΔL/L)

The Attempt at a Solution



A=pir^2
A=pi(.25)^2
Stress = (60)(9.8)/.1963
Y= (588/.1963) / (600/1.44)

I thought everything was set up right.. Need assistance on part 2 also, thanks.
[/B]
 
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Watch those units. Also, arithmetic error.

Chet
 
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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