Calculating Force Using Young's Modulus

AI Thread Summary
To calculate force using Young's modulus, the relevant formulas include stress (σ = F/A) and strain (ε = ΔL/L), leading to the expression E = FL/(AΔL). The discussion highlights a student's attempt to find force, resulting in a calculation of 9812.5N, which was significantly off from the teacher's answer of 981N. The discrepancy is attributed to a potential misplacement of a decimal point. Participants emphasize the importance of clearly stating the problem and showing calculations to identify errors. Accurate calculations and understanding of the formulas are crucial for solving problems related to Young's modulus.
chriscarson
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Homework Statement
Calculating Force when having the area .
Relevant Equations
How can you Calculate Force ?
How can you Calculate Force ?
 
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I'm not sure what the question is specifically. We have ##\sigma = \frac{F}{A}## and ##\varepsilon = \frac{\Delta L}{L}##, along with the definition of Young's modulus, ##E = \frac{\sigma}{\varepsilon}##.

You can put these into one expression, namely ##E = \frac{FL}{A\Delta L}##.
 
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etotheipi said:
I'm note sure what the question is specifically. We have ##\sigma = \frac{F}{A}## and ##\varepsilon = \frac{\Delta L}{L}##, along with the definition of Young's modulus, ##E = \frac{\sigma}{\varepsilon}##.

You can put these into one expression, namely ##E = \frac{FL}{A\Delta L}##.

the question is to find the force
 
chriscarson said:
the question is to find the force

So are you after ##F = \frac{AE\Delta L}{L}##?
 
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etotheipi said:
So are you after ##F = \frac{AE\Delta L}{L}##?

well i have all those values so i can give it a shot , although our teacher give us homework that we didi nt had lesson on ,
thanks
 
was very close the teacher s answer was 981N mine was 9812.5N
 
chriscarson said:
was very close the teacher s answer was 981N mine was 9812.5N
That's what's called being out by a factor of ten. Can you find the reason for it?
 
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PeroK said:
That's what's called being out by a factor of ten. Can you find the reason for it?

i know you can round it to 3 significant figures but nothing about factor of ten.
 
chriscarson said:
i know you can round it to 3 significant figures but nothing about factor of ten.

You should post your calculation along with a statement of the problem. My guess is you've misplaced a decimal point somewhere.
 
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PeroK said:
You should post your calculation along with a statement of the problem. My guess is you've misplaced a decimal point somewhere.

ok it seems it s important to write the problem
 
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