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suju101 Group Title

HELP!!! when a person coughs, the trachea(windpipe contracts, allowing air to be expelled at max velocity. it can be shown that during a cough the velocity v of airflow is given by the function v=f(r)=kx^2(R-r) where r is the radius of the trachea in cm during a cough, R is the trachea's normal radius in cm, and k is a positive constant that depends on the length of the trachea. find the radius r for which the velocity of airflow is greatest.

  • 2 years ago
  • 2 years ago

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  1. mathq Group Title
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    Hey ask it in other greoups

    • 2 years ago
  2. suju101 Group Title
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    which group??

    • 2 years ago
  3. suju101 Group Title
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    this is a maths problem.

    • 2 years ago
  4. mathq Group Title
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    science, biology,

    • 2 years ago
  5. mathq Group Title
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    oh!

    • 2 years ago
  6. mathq Group Title
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    sorry

    • 2 years ago
  7. omar_86 Group Title
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    i think u have to differentiate f(r) to have df(r)/dr, but i can't see what's ment by the "x" in f(r)?

    • 2 years ago
  8. suju101 Group Title
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    sorry...thats "r". v=f(r)=kr^2(R-r)

    • 2 years ago
  9. omar_86 Group Title
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    aha, then: v=kr^2R-kr^2r, where k, R are constants dv/dr=2kRr-3kr^2 finding the maxima by equaling to zero 0=2kRr-3kr^2

    • 2 years ago
  10. suju101 Group Title
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    any particular reason for finding the maxima??

    • 2 years ago
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