State torricelli\'s law for efflux speed of liquid and prove it.

1.	State torricelli\'s law for efflux speed of liquid and prove it.
Answer» Torricelli’s law\tTorricelli law states that the speed of flow of fluid from an orifice is equal to the speed that it would attain if falling freely for a distance equal to the height of the free surface of the liquid above the orifice.\tConsider any vessel which has an orifice (slit)filled with some fluid.\tThe fluid will start flowing through the slit and according to Torricelli law the speed with which the fluid will flow is equal to the speed with which a freely falling bodyattains such that the height from which the body falls is equal to the height of the slit from the free surface of the fluid.\tLet the distance between the free surface and the slit = h\tVelocity with which the fluid flows is equal to the velocity with which a freely falling body attains if it is falling from a height h.Derivation of the Law:-\tLet A1= area of the slit (it is very small), v1= Velocity with which fluid is flowing out.\tA2=Area of the free surface of the fluid,v2=velocity of the fluid at the free surface.\t\t\tFrom Equation of Continuity, Av=constant.Therefore A1v1\xa0= A2v2.\tFrom the figure, A2>>>A1, This implies v2<>Pa.\tTherefore 2gh is ignored as it is very very large, hence\xa0v1= √2P/ρ.The velocity with which the fluid will come out of the container is determined by the Pressure at the free surface of the fluid alone.\t\t

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