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Total energy in a spring?

  • #1

Homework Statement


Since the total energy in a spring is
(1/2)kA^2

Can we rearrange this...
given k=F/x
(1/2)(FA^2/x)

Since x is also the amplitude, we have:
(1/2)(FA)
(1/2)(mgA)

I am pretty sure this is wrong, but why?

Thanks
 

Answers and Replies

  • #2
PhanthomJay
Science Advisor
Homework Helper
Gold Member
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Homework Statement


Since the total energy in a spring is
(1/2)kA^2

Can we rearrange this...
given k=F/x
(1/2)(FA^2/x)

Since x is also the amplitude, we have:
(1/2)(FA)
yes, where F is the max force in the spring and A is the absolute value of x.
(1/2)(mgA)
Only if F = mg, as when a mass is attached from a hanging spring and released.
 

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