Fluids

Definition

Fluids are substances that can flow and conform to the shape of their containers. They include both liquids and gases.

5 Must Know Facts For Your Next Test

1. Fluids have no fixed shape and can flow under applied stress.
2. The density of a fluid is its mass per unit volume, commonly expressed in $\text{kg/m}^3$.
3. Pressure in a fluid at rest is the same in all directions at a given depth, described by Pascal's principle.
4. Buoyancy is the upward force experienced by an object submerged in a fluid due to pressure differences.
5. The continuity equation states that for an incompressible fluid, the mass flow rate must remain constant from one cross-section to another.

Review Questions

• What properties distinguish fluids from solids?
• How does Pascal's principle apply to fluids at rest?
• Explain the concept of buoyancy and how it relates to Archimedes' principle.

Related terms

Density: Density is the mass per unit volume of a substance, typically measured in $\text{kg/m}^3$.

Pascal's Principle: Pascal's Principle states that pressure applied to an enclosed fluid is transmitted undiminished to every part of the fluid and the walls of its container.

Buoyant Force: The buoyant force is the upward force exerted on an object submerged in a fluid, equal to the weight of the displaced fluid.