An approachable introduction to fluid dynamics that links basic hydrostatic ideas (pressure and depth) to fluid motion (continuity, Bernoulli), explains viscosity and flow types (laminar vs turbulent), and highlights biological applications with simple experiments and problem-solving strategies.
Fluid Dynamics — The Wild Ride of Moving Fluids Imagine you're a tiny red blood cell on a roller coaster called the circulatory system. Why does your ride speed up near a squeeze, slow down in a wide chamber, or crash into turbulent whirlpools? Welcome to fluid dynamics — the backstage pass to...
Quick detour: Where this fits (building on what you already learned) You already met density (thanks particle theory!), buoyant force , and Archimedes' Principle . Those ideas tell us why things float or sink and how the mass and spacing of particles control that behavior. Now we move from &q...
The basics: Pressure, depth, and forces in fluids Pressure = force per unit area. When a fluid presses on something, it pushes from all directions. In a fluid at rest, pressure increases with depth because the weight of the fluid above presses down. Simple equation you already can use: Pres...
When fluids flow: continuity and conservation Fluids in motion obey conservation rules. One big idea is that what goes in must come out (for steady flow in a closed pipe): If a tube gets narrower, the fluid must speed up so the same volume passes each second. This is the continuity equation i...
Bernoulli's idea — speed vs pressure (the “speedy air sucks” trick) Bernoulli's principle says: where fluid speed is higher, pressure is lower (for streamlined, non-viscous flow). This is not magic; it's energy conservation for moving fluids. Biological example: blood flowing faster...
Viscosity: fluid stickiness and resistance Not all fluids flow the same. Viscosity is the measure of a fluid's internal friction. Low viscosity = flows easily (water) High viscosity = resistant to flow (honey) Viscosity matters in life science: blood viscosity affects how easily the hea...
Laminar vs Turbulent flow — smooth vs chaotic Feature Laminar flow Turbulent flow Motion Smooth layers sliding Chaotic swirls (eddies) Predictability Predictable Unpredictable Examples Blood in small capillaries Rapids, smoke from a chimney Why care? Turbulence increas...
Real-life life science applications (short and punchy) Blood flow : Narrowed arteries → higher velocity, altered pressure; risk of turbulent flow and clotting. Breathing : Air moves faster in narrowed airways (bronchoconstriction), changing pressure and resistance — asthma moment! Fish and sw...
How to think about problems (quick strategy) Identify whether the fluid is moving or still. If still → use hydrostatic ideas (p = ρgh). If moving, check if the pipe/space changes size → continuity matters. Ask about speed vs pressure trade-offs (Bernoulli) or if stickiness (viscosity) matters...
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