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Bernoulli Effect. Fluid Flow. ● fluids are materials that flow and take on the shape of a container. ● eg . liquids, gases. ● viscosity is the internal friction in fluid caused by the cohesive (attractive) forces between molecules. ● viscous fluids flow slowly. Types of Fluid Flow.
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Fluid Flow ● fluids are materials that flow and take on the shape of a container ● eg. liquids, gases ● viscosity is the internal friction in fluid caused by the cohesive (attractive) forces between molecules ● viscous fluids flow slowly
Types of Fluid Flow Laminar or Streamlined Flow - fluid layers behaves as thin sheets that slide over one another - streamlines parallel - In a pipe, friction slows layers near walls - Parabolic profile
Turbulent Flow ● flow is irregular ● backwards swirls and eddies present ● can occur as fluid flows past an obstacle ● undesirable as kinetic energy converted to sound, heat, etc. ● pipe with blockage
Speed and Fluid Pressure ● as water passes from a wide into narrow pipe it speeds up to maintain the same volume of flow ● speed of flow in region B is faster than in region A VB > VA ● fluid particles have accelerated in going from A to B ● the force causing this acceleration is the difference in fluid pressure PA > PB
Bernoulli’s Principle For an incompressible fluid moving in laminar flow, the pressure of the fluid decreases as the speed increases. Faster Speed Lower Pressure
Applications ● contributes to lift on airplane wing ● backspin on a golf ball allows it to rise high! ● sidespin on a baseball causes a curve ball
Venturi Meter Venturi Flow Meter ●HW: P11,13-15 pg. 105-106 S5-7 pg 107 ●Read over Investigation 1.3.1 pg. 58 Prepare Hypothesis: How will terminal velocity depend on mass of coffee filters dropped?