We will calculate potential energy, in this case, using the next formula
[tex]PE=\text{mgh}[/tex]where m is the mass, g is the gravity and h is the height
in our case
m=87 kg
g=9.8 m/s^2
h=51m
we substitute
[tex]PE=87(9.8)(51)=43482.6J[/tex]ANSWER
The energy is 43482.6J
