4. Fluids Formulas (10%)

Density

• variables: mass, volume

Density of Water (2)

Force of Gravity Applied to an Object/Weight of a Volume of Fluid

• variables: density of object/fluid, volume of object/fluid

(density of liquid or object / density of water)

Specific Gravity (% of an object that is submerged in water — if SG > 1, object will sink)

Pressure

• variables: normal force, area

Pressure units

Absolute Pressure

• variables: ambient/surface pressure, fluid density, depth of object

Gauge Pressure

• variables: absolute pressure, atmospheric pressure

Pascal’s Principle (2)

(remember volume = area x height)

Buoyant Force

• variables: fluid density, volume of fluid displaced/submerged

Critical Velocity/Speed [the flow speed at which the fluid's movement transitions from smooth, orderly (laminar) flow to chaotic, irregular (turbulent) flow]

• variables: fluid viscosity, fluid density, diameter of the tube

Continuity Equation // Flow Rate/Flux

• variables: velocity, cross-sectional areas at 2 points

(essentially PE₁ + KE₁ = PE₂ + KE₂ except you add pressure and replace mass with density)

Bernoulli’s Equation