Answer:
Explanation:
Given
mass of rock [tex]m=40\ kg[/tex]
Elevation of Rock [tex]h=10\ m[/tex]
Distance traveled by rock with time
[tex]h=ut+\frac{1}{2}at^2[/tex]
where, u=initial velocity
t=time
a=acceleration
here initial velocity is zero
when rock is 5 m from ground then it has traveled a distance of 5 m from top because total height is 10 m
[tex]5=0\times t+\frac{1}{2}(9.8)(t^2)[/tex]
[tex]t^2=\frac{10}{9.8}[/tex]
[tex]t=1.004\approx 1\ s[/tex]
velocity at this time
[tex]v=u+at[/tex]
[tex]v=0+9.8\times 1.004[/tex]
[tex]v=9.83\ m/s[/tex]
