Types of Forces Present in a Moving Liquid – The important forces present in a moving liquid are Inertia Force, Viscous Force, Gravity Force, Surface Tension Force, Pressure Force and Elastic Force.

(a) Inertia force: It is the product of mass and acceleration of the flowing liquid.

(b) Viscous force: It is the product of shear stress due to viscosity and the cross-sectional area of flow.

(c) Gravity force: It is the product of mass and acceleration due to gravity of a flowing liquid.

(d) Surface tension force: It is the product of surface tension per unit length and length of the surface of flowing liquid.

(e) Pressure force: It is the product of intensity of pressure and the area of a flowing liquid.

(f) Elastic force: It is the product of elastic stress and the area of a flowing liquid.