A cylindrical tank of Height H has a hole on its side. It is kept on a flat surface. Assuming that hole’s area is much smaller than the area of the tank, what should be the distance of the hole below the top surface so that water coming out of the hole travels the maximum horizontal distance at the instant when the height of water is H?

Bernoulli's equation is a relation between pressure, kinetic energy, and gravitational potential energy of a fluid in a container.