Answer:
[tex]v_f=15.01\ m/s[/tex]
Explanation:
Free Fall Motion
If an object is dropped from a certain height h in free air (no friction), it falls to the ground with an acceleration of gravity ([tex]9.8\ m/s^2[/tex]). The speed of the object is given by
[tex]v_f=g.t[/tex]
And the distance traveled downwards is
[tex]\displaystyle y=\frac{g.t^2}{2}[/tex]
We can find the time the object is in the air before reaching ground level, solving the above equation for t as follow
[tex]\displaystyle t=\sqrt{\frac{2y}{g}}[/tex]
[tex]\displaystyle t=\sqrt{\frac{2(11.5)}{9.8}}[/tex]
[tex]t=1.532\ sec[/tex]
Now we compute the speed
[tex]v_f=9.8(1.532)=15.01\ m/s[/tex]
[tex]\boxed{v_f=15.01\ m/s}[/tex]
