The lower end of a capillary tube of diameter 2.0 mm is dipped 8.00cm below the surface of water in a beaker. What is the pressure required in the tube in order to blow a hemispherical bubble at its end in water? The surface tension of water at temperature of the experiments is `7.30 xx 10^(-2) Nm^(-1)`. 1 atmospheric pressure =` 1.01 xx 10^(5) Pa`, density of water `= 1000 kg//m^(3), g=9.80 ms^(-2)`. also calculate the excess pressure.

Explanation

The pressure required to blow the bubble is
`P=P_("atm")+hdg+2T//r`
`=1.0178xx10^(5)+(2xx7.3xx10^(-2)//10^(-3))`
`=(1.01784+0.00146)xx10^(5)=1.02xx10^(5)Pa`.