Why do we have to multiply the result by 10^3? (Answer is E)
let’s assume artery as a cylinder, with length x mm cross sectional area A and volume as Ax.
the volume of blood flowing through the artery per second is same as the volume of the artery divided by the time it takes one RBC to pass through the length.
so, V=Ax/T therefore A=VT/x.
However A here has units (ml/second x seconds)/mm which is ml/mm whereas we want A in mm^2.
A ml is 1000mm^3 so, we must multiply VT/x by 1000 or 10^3 to get area in mm^2.
Hope it helps:)
Thank you very much, helps a lot!