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Physics 2A

Fluids

PressureBuoyant ForceIdeal FluidsEquation of ContinuityBernoulli’s Principle

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Fluids in Motion

The motion of real fluids is very complicated and is not yet fully understood.

We will only discuss the motion of ideal fluids.

Ideal Fluids

1) Steady Flow: the velocity of the moving fluid at any fixed point does not change with time (not turbulent)

Ideal Fluids

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Ideal Fluids

2) Incompressible Flow: the fluid is incompressible (density is constant)

3) Nonviscous Flow: friction within the fluid can be ignored

4) Irrotational Flow: a tiny test body placed within the fluid will not rotate about an axis through its own center of mass

The equation of continuity:

1A1 v1 = 2A2 v2

the flow speed increases when we decrease the cross-sectional area

A1 v1 = A2v2 (if constant)

Applications of Bernoulli’s Equation Applications of Bernoulli’s Equation

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Applications of Bernoulli’s Equation Applications of Bernoulli’s Equation

Applications of Bernoulli’s Equation Applications of Bernoulli’s Equation

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Applications of Bernoulli’s Equation