1. Pressure:
* Hydrostatic Pressure: This is the force exerted by the weight of the fluid itself. It acts perpendicularly to any surface within the fluid, including the walls of the container. The pressure increases with depth.
* External Pressure: This is pressure applied from outside the container, such as atmospheric pressure. It acts equally in all directions on the fluid and the container walls.
2. Shear Force:
* Viscous Forces: These forces arise from the fluid's viscosity, its resistance to flow. They occur when layers of the fluid move relative to each other. These forces act tangentially to the direction of motion.
* Surface Tension: This force acts on the surface of the fluid and causes it to behave like an elastic membrane. It arises from the cohesive forces between the fluid molecules.
3. Buoyancy Force:
* This force is an upward force exerted by the fluid on an object submerged in it. It is equal to the weight of the fluid displaced by the object.
4. Other Forces:
* Gravity: The gravitational force acts on the fluid, pulling it downwards.
* External Forces: This includes forces like stirring, shaking, or any other external force applied to the container.
In summary, the forces applied to a fluid in a container are:
* Pressure: Hydrostatic and External
* Shear Force: Viscous and Surface Tension
* Buoyancy Force
* Gravity
* External Forces
The specific forces acting on the fluid will depend on the fluid itself (density, viscosity), the shape and size of the container, and the conditions under which the fluid is contained.
