A stone is released from rest from the edge of a building roof 190 m above the ground. Neglecting air resistance, the speed of the stone, just before striking the ground, is:___________.
If the stone is realeased from rest, this means that its initial velocity is 0.
As tha stone is only influenced by gravity, and the acceleration due to it is constant (near the surface of the Earth), we can apply the following kinematic equation:
[tex]v_{f}^{2} - v_{o}^ {2} = 2* g* h (1)[/tex]
Replacing by the values of g=9.8 m/s², and h=190 m, rearranging and solving for vf, we get:
vf = √2*g*h =√2*9.8 m/s²*190 m = 61 m/s (assuming that the downward direction is the positive one).
