Potential energy of the man relative to the ground can be calculated by using the formula,
P.E = mgh
Here, m is the mass of the man = 70 kg
g is acceleration due to gravity = 9.8 m/s²
h= height above the ground = 4 m
Substituting the value we get,
Potential energy of the man= 70×9.8×4= 2744 J