We know , gravitational force is a conservative force .
Therefore , total energy of the system remains constant .
[tex]P.E_i+K.E_i=P.E_f+K.E_f[/tex]
Let , mass of object is m.
So ,
[tex]mg(2)+0=0+\dfrac{mv_f^2}{2}\\\\v_f=\sqrt{4g}\\\\v_f=\sqrt{4\times 9.8}\ m/s\\\\v_f=6.26\ m/s[/tex]
Therefore , the velocity at floor is 6.26 m/s .
Hence , this is the required solution .
