AP Physics 2 · Unit 1
Fluids: every key term you need
11 flashcard terms for AP Physics 2 Unit 1, written to match the course framework. Study them here, then drill them as interactive flashcards — free, no account needed.
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Fluid Properties Fluids (liquids, gases) flow and conform to container shape. Density ρ = m/V. Compressibility differs: liquids mostly incompressible, gases highly compressible.
Pressure Definition Force per unit area: P = F/A. Units: pascals (Pa), atmospheres (atm), bars. Pressure same in all directions in stationary fluid.
Hydrostatic Pressure Pressure in fluid at depth h: P = ρgh + P₀ where P₀ is surface pressure. Pressure increases linearly with depth.
Buoyant Force (Archimedes) Upward force on submerged object = weight of displaced fluid. Fb = ρVg (V = volume of object). Net force = Fb - mg determines if floats/sinks.
Density & Buoyancy Object floats if ρ_object < ρ_fluid. Sinks if ρ_object > ρ_fluid. Floats partially submerged if ρ_object = ρ_fluid.
Continuity Equation For incompressible flow: A₁v₁ = A₂v₂ (flow rate constant). Narrower tube → faster flow.
Bernoulli's Principle P + ½ρv² + ρgh = constant along streamline. Higher velocity → lower pressure. Explains lift, atomizers, venturi tubes.
Pascal's Principle Pressure applied to enclosed fluid transmitted undiminished throughout. Enables hydraulic systems (pressure distributed equally).
Surface Tension Cohesive forces at liquid surface create 'elastic' behavior; enables insects to walk on water, creates droplets, capillary action.
Viscosity Fluid's resistance to flow; molasses high viscosity, water lower. Viscous drag F = 6πηrv (Stokes' law) proportional to velocity.
Unit 1 Summary Pressure increases with depth; buoyant force enables floating/sinking analysis. Fluid flow (continuity, Bernoulli) relates velocity/pressure. Practical: hydraulics, pumps, lift.
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