What is the Maximum Constriction Radius in the Artery Given These Conditions?

[Dillion]

Homework Statement

A person has a 5200 N/m^2 gauge pressure in a 0.01m radius artery, with blood flowing at 0.5 m/s. the gauge pressure outside the artery is 3200 N/m^2. When using her stethoscope, a physician hears a fluttering sound farther along the artery. the sound is a sign that the artery is vibrating open closed, which indicates there must be a constriction in the artery that has reduced its radius and subsequently reduced the internal blood pressure to less than the external 3200 N/m^2 pressure. What is the maximum artery radius at this constriction?

Homework Equations

Flow rate = Volume/Time

Velocity of cylindrical vessel = Flow rate/Area

A = pi*r^2

Force is equal throughout

The Attempt at a Solution

Not a clue. There are 6 people in my class working on this together

 

[Chestermiller]

By any chance, are you learning about the Bernoulli equation?