Water is filled in a uniform container of area of cross section `A`. A hole of cross section area a `( lt lt A)` is made in the container at a height of `20 m` above the base. Water streams out and hits a small block on surface at some distance from container. Block is moved on surface in such a way that stream always hits the block. The initial velocity of the block (in `m//s`) is (Given `(a)/(A)=(1)/(20)`). (Take `g=10ms^(-2)`)