MCAT Physics Module I: Bernoulli's Eq

MCAT cards made by me for this lesson

pgh stands for what part of the Bernoulli Equation?

PE

The kinetic energy part of the Bernoulli Equation can be found ….

through 1/2 pv²

Bernoulli’s Equation

P1+pgh1+1/2pv²=P2+pgh2+1/2pv²

If a fluid is moving faster in a certain section of the container, what must that tell us about the pressure in that region? 

the pressure must be lower in the region 

Based on Bernoulli’s Equation, if we have a tube that runs underground and all of sudden inclines and then plateus at a new height and the cross sectional area of the tube also gets smaller, what would happen to the pressure as fluid goes from the original point to this new region of the tube?

Lowers pressure; balancing Bernoulli’s equation

Water is circulating through a continuous solid pipe in a house. If the water is pumped at a velocity of 0.6 m/s through a diameter of 10 cm in the basement under a pressure of 3.039×10^5 N/m². What is the flow speed and pressure in a 4.0 cm diameter pipe 6.0 m above?

1.) calculate the velocity; v2:

A1v1=A2v2

v2=A1v1/A2= [(pi(0.05)²(0.6)]/(pi(0.02)²)= 3.75 m/s

2.) calculate the pressure:

P1+1/2pv²=P2+1/2pv²+pgh
P2=(3.039×10^5 N/m²)1/2(1000)(0.6)²-1/2(1000)(3.75)²-(1000)(10)(6)

How is viscosity measured if you have a container with a fluid, with two plates (one stationery and one moving above) between which the fluid flows? 

viscosity=Fd/Av

Units card! What are the units for viscosity? How can they be written in Newtons? Are there are other units available?

Pa*s= N*s/m² or 1/10 Pa*s= 1 Poise

If the viscosity coefficient does not depend on speed; then its a….

Newtonian fluid

Poiseulle’s Equation assumes what two things must be true and then write it out.

a) incompressible fluid and laminar flow
b.) Q=(pi)R⁴(delta P)/ 8 n l

Reynold’s number purpose

What’s the first speed you might expect turbulence; R n/ 2 p r = vcrit

Fluids flow ___ through constricted regions and often means lower pressure.

faster

Using the Venturi Effect, which of the following correctly describes why an airplane is lifted off the ground?

a) the velocity of air under the wings is greater than above, creating greater pressure below and giving lift
b) the velocity of the air under the wings is greater than above, creating less pressure under and giving lift
c) the velocity of the air under the wings is less than above, creating higher pressure below and giving lift
d) the velocity of the air under the wings is less than above, creating lower pressure under and giving lift

C

Assuming constant flow, even a slight change in the radius has significant effect on the ____?

pressure gradient

How do the following concepts relate to one another: Venturi effect, Bernoulli’s equation, and continuity equation? What relationship does it describe?

The continuity equation describes the relationship of flow and cross-sectional area in a tube, while Bernoulli describes the relationship between height, pressure, and flow. The Venturi effect is the direct relationship between area and pressure, and results from the combined relationship of the these equations.

What effect would increasing each of the following have on flow rate: radius of tube, pressure gradient, and length of the tube? 

increase, increase, decrease, decrease