The ball fell from a height of 80m during which time it fell to the ground.

The ball moves from a state of rest under the action of only the force of gravity m * g with the acceleration of gravity g.

For uniformly accelerated motion without an initial velocity, the height of the fall h is determined by the formula: h = g * t ^ 2/2, where g is the acceleration of gravity, t is the time of the fall.

t = √ (2 * h / g).

t = √ (2 * 80 m / 9.8 m / s ^ 2) = 4.04 s.

Answer: the fall of the ball lasts t = 4.04 s.