Potential energy negative, force & displacement co-linear?

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SUMMARY

The discussion centers on the calculation of gravitational potential energy (V_g) in a scenario involving a mass impacting a spring. The formula used is V_g = mgh_2 = (50)(9.81)(-x sin 20), where the negative sign arises from the displacement being in the opposite direction of the gravitational force. This indicates that the object is moving downward, which results in negative potential energy when calculated from a reference point above the object. The confusion stems from the relationship between force, displacement, and the sign convention used in physics.

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Homework Statement


In the following question, in the solution, why is it that when they calculate the gravitational potential energy at point 2 (impact with spring), it is negative? I know that if both the force and displacement act in the same direction, then the work done should be positive. Why is it not the same thing here?
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I think they mean both answers could work when the equation is solved...however one answer would obviously make more sense in this case.
 
Oh sorry about that being un-clear. I mean for $$V_g = mgh_2 = (50)(9.81)(-x \sin 20)$$

why is it negative?
 

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