1. The problem statement, all variables and given/known data By How much does the pressure in a cylinderical jet of water 4mm in diameter exceed the pressure of the surrounding atmosphere if the surface tension of water is 0.0718 N/M? 2. Relevant equations 3. The attempt at a solution ΔP= σ/r=0.0718/2*10^-3 , This is the answer I have but I don't understand from where did he get this law . Isn't it supposed to be ΔP= 2σ/r instead ?