Question: When a foreign object lodged in the trachea (windpipe) forces a person to cough, the diaphragm thrusts upward causing an increase in pressure in the

When a foreign object lodged in the trachea (windpipe) forces a person to cough, the diaphragm thrusts upward causing an increase in pressure in the lungs. This is accompanied by a contraction of the trachea, making a narrower channel for the expelled air to flow through. For a given amount of air to escape in a fixed time, it must move faster through the narrower channel than the wider one. The greater the velocity of the airstream, the greater the force on the foreign object. x rays show that the radius of the circular tracheal tube contracts to about two-thirds of its normal radius during a cough. According to a mathematical model of coughing, the velocity of the v airstream is related to the radius of the trachea by the equation
V(r) = k(r0 - r)r2............1/2r0 ≤ r ≤ r0
where is a constant and r0 is the normal radius of the trachea. The restriction on is due to the fact that the tracheal wall stiffens under pressure and a contraction greater than 1/2 r0 is prevented (otherwise the person would suffocate).
(a) Determine the value of r in the interval [1/2r0, r0] at which v has an absolute maximum. How does this compare with experimental evidence?
(b) What is the absolute maximum value of on the interval?
(c) Sketch the graph of on the interval [0, r0].

Step by Step Solution

3.55 Rating (172 Votes )

There are 3 Steps involved in it

1 Expert Approved Answer
Step: 1 Unlock

a vr k 0 2 kr 0 r 2 kr 3 vr 2kr 0 r 3kr 2 vr 0 kr2r 0 3r 0 r 0 or 23r 0 bu... View full answer

blur-text-image
Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock
Step: 3 Unlock

Document Format (1 attachment)

Word file Icon

786-C-D-E (570).docx

120 KBs Word File

Students Have Also Explored These Related Calculus Questions!