Magnetic forces cause an excess of positive ions to flow along one side of the artery and negative ions on the opposite side. What is the greatest possible potential difference across the artery?

A sodium ion (Na⁺) moves along with the blood in an artery of diameter 1.0 cm. The ion has mass 22.99 u and charge ⁺e.
The maximum blood speed in the artery is 4.25 m/s. Earth's magnetic field in the location of the patient has magnitude 30 μT.