The potential energy U of an object with mass m located a distance h above the ground is given by the expression:
[tex]U=mgh[/tex]Where g=9.81m/s^2 is the gravitational acceleration on the surface of Earth.
Since the 2.85kg object is located 12.7 meters below the ground, we can consider h to be negative. Replace m=2.85kg, g=9.81m/s^2 and h=-12.7m to find the potential energy of the object measured from the ground level:
[tex]U=mgh=(2.85kg)(9.81\frac{m}{s^2})(-12.7m)=-355.07...J[/tex]Therefore, the potential energy of the object measured from the ground level is approximately 355J.
