Physics Help Forum Stretching of string (and tearing of string)

 Energy and Work Energy and Work Physics Help Forum

 Jul 8th 2017, 05:27 AM #11 Junior Member   Join Date: Jul 2017 Posts: 27 Also, it is mentioned this: d2l/dt2 = (F/2) / (ρdl) = F/(2m) m - mass If that can actually help for better explanation of the context...
 Jul 8th 2017, 05:31 AM #12 Senior Member   Join Date: Apr 2015 Location: Somerset, England Posts: 1,035 Looks like average force to me as I said. Or if you prefer average acceleration since the acceleration varies from zero to max in a vibrating string.
Jul 8th 2017, 05:49 AM   #13
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 Originally Posted by studiot Looks like average force to me as I said. Or if you prefer average acceleration since the acceleration varies from zero to max in a vibrating string.
So:
1) the equation is form of F=ma;
2) "2" stays for the fact that the maximum stress is twice the average stress.

Right?

 Jul 8th 2017, 05:54 AM #14 Senior Member   Join Date: Apr 2015 Location: Somerset, England Posts: 1,035 Works for me. For your information the (strain) energy involved in stretching a string E = 1/2 Max stress x strain = work done in raising the stress from zero to max. This is also = 1/2 Load x extension I also think that the connection to waves is that your article must be about vibrating strings. It would not involve Newton's Second Law for static stretching. Last edited by studiot; Jul 8th 2017 at 06:00 AM.
Jul 8th 2017, 06:09 AM   #15
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 Originally Posted by studiot Works for me. For your information the (strain) energy involved in stretching a string E = 1/2 Max stress x strain = work done in raising the stress from zero to max. This is also = 1/2 Load x extension I also think that the connection to waves is that your article must be about vibrating strings. It would not involve Newton's Second Law for static stretching.
That's right!

I am re-examining the text now- it's all about vibrating string, not about static straining.