For this case we have that by definition, the potential energy of an object is given by:
[tex]U = mgh[/tex]
Where,
Substituting values we have:
[tex]U = (2) (9.8) (4)\\U = 78.4 J[/tex]
Answer:
Relative to the ground its potential energy is:
[tex]U = 78.4 J[/tex]