Question | Answer |
Viscosity | The measure of internal friction in a fluid, often denoted by η. |
Specific Gravity | A dimensionless quantity given by the density of a substance divided by the density of water, where ρ[water] = 1 g/mL or 1 g/cm^3. |
Streamline | Lines that trace the path of water particles as they flow in a tube without ever crossing each other. |
Turbulent Flow | Type of liquid flow that occurs when the flow rate in a tube exceeds V[C]. The motion of the fluid that is not adjacent to the container walls is highly irregular, forming vortices and a high flow resistance. |
Young's Modulus | A term used in characterizing the elasticity of a solid, denoted by Y and measured by the ratio of the stress (F/A) to strain (ΔL/L). Results when force is applied perpendicular to the surface area. |
Absolute Pressure | The pressure below the surface of a liquid that depends on gravity and surface pressure, calculated by P = Po + ρgz, where P is the absolute pressure, z is depth, and Po is the surface pressure. |
Adhesion | A type of attractive force that molecules of a liquid feel toward molecules of another substance, such as in the adhesion of water droplets to a glass surface. |
Archimedes' Principle | A body that is fully or partially immersed in a liquid will be buoyed up by a force that is equal to the weight of the liquid displaced by the body. F[buoyant] = ρ[liq] g V[liq] = ρ[obj] g V[obj], where V[obj] is the volume of the object submerged. |
Bernoulli's Equation | Equation describing the conservation of energy in fluid flow, given by P[1] + 1/2 ρ V[1]^2 + ρgy[1] = P[2] + 1/2 ρ V[2]^2 + ρgy[2]. |
Bulk Modulus | A term that describes a fluid's resistance to compression under a pressure, denoted by B and measured by the ratio of stress (pressure change) to strain: ΔP / (ΔV/V). |
Cohesion | A type of attractive force felt by liquid molecules toward each other. Cohesion is responsible for surface tension. |
Continuity Equation | The equation following the law that the mass flow rate of fluid must remain constant from one cross-section of a tube to another, given by A1V1 = A2V2. |
Density | A scalar quantity defined as the mass per unit volume, often denoted by ρ. |
Gauge Pressure | The pressure above the atmospheric pressure, given only by ρgz; the difference between P[absolute] and Po. |
Laminar Flow | The simplest type of liquid flow through a tube where thin layers of liquid slide over one another, occurring as long as the flow rate remains below a critical velocity V[C]. |
Pascal's Principle | Principle stating that when a pressure is applied to one point of an enclosed fluid, that pressure is transmitted in equal magnitude to all point within that fluid and to the walls of its container. This principle forms the basis of the hydraulic lift. |
Shear Modulus | A term describing a solid's resistance to shear stress, denoted by S and measured by the ratio of shear stress (F/A) to strain (x/h). Results when a force is applied parallel to the surface area. |