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

A 2.00-kg object is hanging from the end of a vertical spring. The spring constant is 50.0 N/m. The object is pulled 0.200m downward and released from rest. Complete the table below by calculating the translational kinetic energy, the gravitational potential energy, the elastic potential energy, and the total mechanical energyEfor each of the vertical positions indicated. The vertical positionshindicate distance above the point of release, whereh= 0.

h(meters) KE PE(gravity) PE(elastic)E

0

0.200

0.400

2. Relevant equations

E_{f}=E_{0}(Conservation of mechanical energy)

K = .5mv^{2}U_{s}= .5kx^{2}U_{g}= mgh

3. The attempt at a solution

I got all of the gravitational potential energies ( 0 , 3.92J , 7.84J) using U_{g}= mgh and KE at 0, where v = 0. For the elastic potential energy at 0, I thought that you would be able to use .5kx^{2}with x = 0.200m, but that doesn't give the right answer (which is 8.76 J). I think the answer has something to do with the equation for conservation of mechanical energy, but what I tried didn't yield a correct answer or even make much sense. I'm probably missing something obvious, but I would appreciate some help.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Energy and Simple Harmonic Motion of spring

**Physics Forums | Science Articles, Homework Help, Discussion**