PHYSICS HELP URGENT!!! While standing at the edge of the roof of a building, a man throws a stone upward with an initial speed of 7.59 m/s. The stone subsequently falls to the ground, which is 18.9 m below the point where the stone leaves his hand. At what speed does the stone impact the ground? Ignore air resistance and use =9.81 m/s2 for the acceleration due to gravity. I need help finding out the impact speed, please.

Respuesta :

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.