Answer:
The cannon ball hits the ground with a speed of 76.35 m/s.
Step-by-step explanation:
We shall use the conservation of energy principle to solve the problem
The initial energy of the cannon ball is the sum of the potential and the kinetic energies.
We know that potential energy =

Applying the given values we obtain the initial potential energy as

Similarly the initial kinetic energy of the ball equals

Applying values we get

Thus the initial energy is thus

Now upon hitting the ground the only energy that the cannon ball will posses is kinetic energy since the potential energy of any object upon touching the surface of earth equals zero
Thus we have

Equating initial and final energies we get
