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DorelXD
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Homework Statement
An elastic wire has the folowing charcteristics:initial length [itex]l_0=60cm[/itex],section [itex]S=6mm^2[/itex],Young's Modulus [itex]E=\frac{12MN}{m^-2}[/itex].Initially the wire has both ends fixed. Its initial position is horizontal, untensioned. At the middle of the wire it's hanged a body that produces an elongation equal to 8 cm. Find the potential energy of deformation stored in the wire, when the body reaches its equilibrium position.
Homework Equations
[tex]\frac{F}{S}=E\frac{Δl}{l_0}[/tex]
[tex]F_e=kx[/tex]
[tex]E_e=\frac{k*Δl^2}{2}[/tex]
The Attempt at a Solution
Well what bugs me is that I don't know what to do with the elongation in the problem. It confuses me that we pull from the middle of the wire, and not from one of its ends. Can somebody help me to understand this problem, please? Also I don't know what the spring constant is.