# Energy conservation question

## Main Question or Discussion Point

In the attached picture below I am compressing a spring...
In picture 2, I've compressed the spring a distance x and thus the elastic potential is 1/2 kx^2 and the total energy in the system AT THAT POINT is 1/2 kx^2 + mgh, isn't it? (m is the mass of the ball and h the height from my reference level, the floor) Or am I wrong in thinking this?
Assuming energy conservation, let's say I let go of the spring and it's at that point where it has JUST gone over the edge of the table with its constant horizontal velocity Vx; would the total energy at that point be equal to 1/2 mVx^2 (where m is the mass of the ball) or would I be wrong in assuming this?
Thanks for any help.

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Pseudo Statistic said:
In the attached picture below I am compressing a spring...
In picture 2, I've compressed the spring a distance x and thus the elastic potential is 1/2 kx^2 and the total energy in the system AT THAT POINT is 1/2 kx^2 + mgh, isn't it? (m is the mass of the ball and h the height from my reference level, the floor) Or am I wrong in thinking this?
Your thinking seems correct. That would be the total mechanical energy of the ball/spring/earth system.

Assuming energy conservation, let's say I let go of the spring and it's at that point where it has JUST gone over the edge of the table with its constant horizontal velocity Vx; would the total energy at that point be equal to 1/2 mVx^2 (where m is the mass of the ball) or would I be wrong in assuming this?
You forgot the gravitational PE (mgh). The total mechanical energy at that point would be its KE + mgh.

Alright so, the mghs in the equality would cancel out leaving us with 1/2mv^2 = 1/2 kx^2, wouldn't it?