To solve this problem we will apply the concepts related to potential gravitational energy. This is defined as the product between mass, acceleration and change in height and can be expressed as,
[tex]\Delta PE = mg \Delta h[/tex]
Here,
m = Mass
g = Gravitational acceleration
[tex]\Delta h[/tex] = Height
Replacing with our values we have,
[tex]\Delta PE = (15kg)(9.81m/s^2)(13m-7m)[/tex]
[tex]\Delta PE = 882.9J \approx 883J[/tex]
Therefore the change in gravitational potential energy is 883J.
