# Different types of forces acting in moving liquid

The important forces present in a moving liquid are as follows

- Inertial force
- Viscous force
- Gravity force
- Pressure force
- Surface tension force
- Elastic force

**Inertial force**: It is equal to the product of mass and acceleration of the flowing fluid and acts in the direction opposite to the direction of acceleration. It always exists in the fluid flow problems.**Viscous force :**It is equal to the product of shear stress due to viscosity and surface area of the flow. It is present in fluid flow problems where viscosity is having an important role to play.**Gravity force :**It is equal to the product of mass and acceleration due to gravity of the flowing fluid. It is present in case of open surface flow.**Pressure force :**It is equal to the product of pressure intensity and cross sectional area of the flowing fluid. It is present in case of pipe flow.**Surface tension force :**It is equal to the product of surface tension and length of surface or flowing fluid**Elastic force :**It is equal to the product of elastic stress and the area of flowing fluid.