(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Consider a spring with spring constant k = 8.42 N/m with an unstretched length of 0.250 m. How much work do you do on the spring in stretching it from a length of L1 = 0.450 m to a length of L2 = 0.559 m?

2. Relevant equations

F= kx

W=(1/2) kx^2

3. The attempt at a solution

since work is area under the curve of x vs. F graph, I did:

W=(1/2)(8.42)(0.559-0.450)^2 = 0.0500 J (wrong answer)

wrong maybe because this works only when u start at the unstretched length?

So I also tried W= (1/2) k xf^2 - (1/2) k xi^2 [where xf = 0.559 and xi=0.450)

=0.464J (still wrong)

What am i doing wrong?

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# Homework Help: Spring force and work

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