A4kg ball is on a 5 m ledge. if it is pushed off the ledge, how much kinetic energy will it have just before hitting the ground?

According to law of conservation of energy;
potential energy at the top = kinetic energy at the bottom
as the ball travels downwards, its potential energy is converted into kinetic  energy
potential energy (pe) = mass(m)×gravitational acceleration(a)×height(h)
where m= 4  kg, a= 9.8 m/s² and h =5 m
kinetic energy(ke)= 0.5×mass(m)×velocity(v)²
where m=4 kg, and v = ?
pe = 4×9.8×5=196 j
since pe = ke
ke=196  j