A cylinder of height 20 m is completely filled with water. The velocity of efflux of water (in ms−1) through a small hole on the side wall of the cylinder near its bottom, is :

Apply the Bernoulli’s theorem just inside and outside the hole. Take reference line for gravitational potential energy at the bottom of the vessel.Let P0 is the atmospheric pressure, ρ the density of liquid and v the velocity at which water is coming out.Pinside+ρgh+0=Poutside+ρv22⇒P0+ρgh=P0+ρv22⇒v=2gh=2×10×20=20m/s