A spherical drop of water has r=0.1mm . If the surface tension of water is 72 dynes/cm , calculate the pressure difference across the interface. Express your answer in dynes/cm^2 , atmospheres( 1 atm = 1.013 × 10^6 dynes/cm^2) , and psia (a atm = 14.7 psia) . Tip: theta=0 for perfect fluid spheres.