Answer:
1.543
Explanation:
According to Poiseuille's law, blood flow (Q) is given by:
[tex]Q= \frac{\pi *\Delta P*r^4}{8*\mu*L}[/tex]
Where ΔP is the blood pressure difference, μ is the blood viscosity, r is the radius of the blood vessel, and L is the length of the vessel.
During a marathon, the new radii of her blood vessels (r') are
[tex]10*Q= \frac{\pi *1.5\Delta P*(k*r)^4}{8*0.85\mu*L}\\5.667*Q= \frac{\pi *\Delta P*(k*r)^4}{8*\mu*L}\\k^4=5.667\\k=1.543[/tex]
The average radii of her blood vessels increased by a factor of 1.543
