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# Elastic string energy question? watch

1. If i have a string which i pull and extend beyond it's antural length and then let go, what will the enrgy composition be like when the string first becomes slack? Would it be Gravitational PE and Kinetic Energy? For example when it is extended all the nergy is elastic potential, but when it is let go for when it first becomes slack does it become a mixture of kinetic energy and GPE, i thought because if the string is slack there'd be no extension or Elastic Potential. Also for the GPE what would the value of h be in mgh? would it be the natural length?

btw sting is connected at one end at the ceiling and the other end to a mass
2. (Original post by ErniePicks)
If i have a string which i pull and extend beyond it's antural length and then let go, what will the enrgy composition be like when the string first becomes slack? Would it be Gravitational PE and Kinetic Energy? For example when it is extended all the nergy is elastic potential, but when it is let go for when it first becomes slack does it become a mixture of kinetic energy and GPE, i thought because if the string is slack there'd be no extension or Elastic Potential. Also for the GPE what would the value of h be in mgh? would it be the natural length?

btw sting is connected at one end at the ceiling and the other end to a mass
Hello there,

I am assuming that the string is being suspended vertically during this example. When the string becomes slack after release, all of the energy that was stored as elastic potential energy gets converted into kinetic energy. There is no net gain or loss of gravitational potential energy between the times when it was its natural length and when it becomes slack (when it is just under its natural length). It is only after the string becomes slack that it begins to gain gravitational potential energy as it rises (whilst losing kinetic energy as it slows down). To reiterate, the only energy the string has when it first becomes slack is kinetic energy (measuring gravitational potential relative to the point of suspension).

I hope that this has been helpful. Please tell me if I have been unclear.
3. (Original post by Smithenator5000)
Hello there,

I am assuming that the string is being suspended vertically during this example. When the string becomes slack after release, all of the energy that was stored as elastic potential energy gets converted into kinetic energy. There is no net gain or loss of gravitational potential energy between the times when it was its natural length and when it becomes slack (when it is just under its natural length). It is only after the string becomes slack that it begins to gain gravitational potential energy as it rises (whilst losing kinetic energy as it slows down). To reiterate, the only energy the string has when it first becomes slack is kinetic energy (measuring gravitational potential relative to the point of suspension).

I hope that this has been helpful. Please tell me if I have been unclear.
ahhhh yes thank you very much!
4. (Original post by ErniePicks)
ahhhh yes thank you very much!
You're very welcome.

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