- #1
iamtrojan3
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Homework Statement
Find the minimum diameter of an l = 17.2 m long steel wire that will stretch no more than 7.38 mm when a mass of 323 kg is hung on the lower end. (Hint: The Young's modulus of steel is 200.0 GPa.)
Homework Equations
Youngs = (Force / Area) / (change L / L)
= (mg / pi*r^2) / (change L / L)
The Attempt at a Solution
Simple enough... just plug and chug right?
just to clarify, 200.0GPa = 2x10^11 N/m^2 correct?
and 7.38mm = 0.00738m
If so,
Then after solving for r... i got .006853m, which is wrong. And i did multiply by 2 for the diameter. 0.0685 is also wrong, so is .685m
What am i doing wrong?? or am i just way off??
Thanks