One end of a uniform glass capillary tube of radius $r=0.025\;cm$ is immersed vertically in water to a depth $h=1\;cm$. The excess pressure in $N/m^2$ required to blow an air bubble out of the tube: (Surface tension of water$= 7 \times 10^{-2} N/m$ Density of water$= 10^3 kg/m^3$ Acceleration due to gravity $=10 m/s^2$)