Reading Quiz 21 Key

Due 3:30 pm, Tuesday, November 10th

Physics 105, Fall Term, 2009


Reading: Chapter 9.7

Did you complete the reading assignment?

Yes
No

KEY CONCEPTS:

1) A fluid includes both liquids and gases.

2) Fluids flow according to Bernoulli's Principle.

Although all fluids have viscosity, or internal friction which in part determines the flow of a fluid, most fluids can be accurately described using Bernoulli's Principle. Bernoulli's principle is really just a the law of conservation of energy in a different form. Rather than using total energy, Bernoulli's Principle is based on energy densities, or the amount of energy in a specific area.

Go to: http://home.earthlink.net/~mmc1919/venturi.html and scroll about half way down the website until you see the pipe applet. On the applet you can change the width of the pipe at four different spots. Additionally, you can see the graphs of the pressure, flow rate, area, and velocity for each part of the pipe directly below the applet. Make several different pipe shapes while noticing how each shape affects the graphs.

What happens to the flow rate when the width of the pipe is increased?

Increases flow rate
Decreases flow rate
Does not change flow rate

What happens to the pressure when the width of the pipe is increased?

Increases pressure
Decreases pressure
Does not change pressure

What happens to the velocity of the fluid when the width of the pipe is increased?

Increases velocity
Decreases velocity
Does not change velocity

Explain why velocity of a fluid is influenced by the cross-sectional area of the pipe as answered in the question above.

An aneurysm is a condition where a portion of an artery balloons out causing a larger cross-sectional area and thinner arterial wall. What affects will this have on the blood flow in the artery? (select all that apply)

Increases flow rate
Decreases flow rate
Increases pressure
Decreases pressure
Increases velocity
Decreases velocity

Why is an aneurysm dangerous?


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Was there anything that you didn't understand in the reading assignment?  What was confusing to you?


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