0.07 m X pi
= 0.2198 m^2 No that’s the circumference!
(And pi = 3.14)
Pressure (P) of 1 bar = 100,000 pa = 750 mmHg = 14.5 psi = 29.5 "Hg
Better to keep everything in inches and psi Army. 70mmØ = 6in^2 within a cats whisker and that makes all the calculations mental arithmetic. Let’s keep it simple. It’s the dynamics that are disputed not the accuracy of the figures. I’m just using P = 15psi for simplicity.