Here, we can use the third equation of motion, [tex]v^{2} = u^{2} - 2as[/tex]
whereas v represents the final velocity, u represents initial velocity, a is the acceleration due to gravity and s is the displacement or distance an object traveled
Here, the initial velocity of the the ball is given as zero and the acceleration due to gravity is 9.8 , the distance 's' is given as 20 m
Using the equation, [tex]v^{2} = 2 * 9.8 * 20 = 392\\v = \sqrt{392} = 19.7m/s[/tex]
