Question

initial speed (in m/s) with which the water flows from the orifice.

Answer 1

Area of orifice $A_o={10}^{-4}$ $m^2$

Area of the surface $A=\pi r^2=\pi \times 1^2=3.14$ $m^2$ $⟹A_o<<A$

Velocity of water flows $v=\sqrt{2gh}$ for $A_o<<A$

$⟹v=\sqrt{2\times 10\times 5}=10$ $m/s$