Answer:
2.36 m/s
Explanation:
We know that F=ma hence considering the frictional force on stone
2=20a
a=2/20= 0.1
From kinematics equations
[tex]v^{2}= u^{2}+2as[/tex]
When it comes to rest , v=0
[tex]u^{2}=2as[/tex]
[tex]u^{2}=2\times 0.1\times 27.9[/tex]
[tex]u=\sqrt {2\times 0.1\times 27.9}=2.36 m/s[/tex]