Answer:
v = 20.69 m/s
Explanation:
Given that,
Initial speed of a stone, u = 7.59 m/s
he stone subsequently falls to the ground, which is 18.9 m below the point where the stone leaves his hand, h = 18.9 m
We need to find the speed of the stone impact the ground. Let the speed be v. Using the equation of kinematics to find v. So,
[tex]v^2-u^2=2as[/tex]
Here, a = g
So,
[tex]v^2=2gs+u^2\\\\v=\sqrt{2gs+u^2} \\\\v=\sqrt{2\times 9.81\times 18.9+(7.59)^2} \\\\v=20.69\ m/s[/tex]
So, the speed of the stone impact the ground is 20.69 m/s.