Answer:
78.4 J
Explanation:
The gravitational potential energy of the ball (relative to the ground) is given by
[tex]U=mgh[/tex]
where
m = 2 kg is the mass of the ball
g = 9.8 m/s^2 is the acceleration due to gravity
h = 4 m is the height of the ball above the ground
Substituting numbers into the formula, we find
[tex]U=(2 kg)(9.8 m/s^2)(4 m)=78.4 J[/tex]
