WEBVTT

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This is Giancoli Answers
with Mr. Dychko.

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Poiseuille's equation says that
volume rate of flow

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would be <i>π</i> times the radius of this
oil pipe to the power of 4

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times the pressure difference divided by
8 times the viscosity of the oil

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times the length of the pipe.

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So we can solve for pressure difference
<i>P 1</i> minus <i>P 2</i> by multiplying

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both sides by 8<i>ηl</i> over <i>πR</i>
to the power of 4

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and we get the pressure difference is

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8 times the viscosity times the length
times the volume rate of flow

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divided by <i>π</i> times the radius
to the power of 4.

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So we have 8 times 0.2 pascal seconds—
viscosity for the oil—times

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1.6 times 10 to the 3 meters,

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convert the kilometers into meters there,

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times by 650 cubic centimeters per second

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which we have to convert into
cubic meters per second

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by multiplying by 1 meter for every
100 centimeters cubed

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and then divide by <i>π</i> times 29 centimeter—
diameter—divided by 2

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converted into meters by multiplying by
1 meter for every 100 centimeters

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and raise that result to the power of 4

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and on the calculator it looks like this

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and that's about 1200 pascals
pressure difference.