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

A 0.25 kg object is suspended on a light spring of spring constant 49 N/m. The spring is then compressed to a position 15 cm above the stretched equilibrium position. How much more energy does the system have at the compressed position than at the stretched equilibrium position?

3. The attempt at a solution

[PLAIN]http://img35.imageshack.us/img35/3553/unledbg.jpg [Broken]

[tex]E_{total} = PE_{spring} + PE_{regular potential energy}[/tex]

So before it has been stretched by the mass

[tex]mg = ky[/tex]

[tex]y = mg/k = (0.25kg)(10m/s^2)/(49N/m) = 0.051m[/tex]

Now I am stuck...

Is the total energy

[tex]\sum E_i = mgy[/tex]

[tex]\sum E_i = \frac{1}{2}ky^2[/tex]

[tex]\sum E_i = \frac{1}{2}ky^2 + mgy[/tex]

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# Homework Help: Total energy system

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