An air bubble of `10mm` radius is rising at a stready rate of `2mm//sec` through a liquid of density `1.47xx10^(8) kg m^(-3)` . Calculate the coffe. Of viscosity of liquid `(g=9.8 ms^(-2))` neglect density of air.

Explanation

`v=(2pi r^(2) rho g )/(9 eta)` or `eta=(2pi r^(2) rho g)/(9 v)`
`=(2xx(10xx10^(-3))^(2)xx1.47xx10^(3)xx9.8)/(9xx(2xx10^(-3)))`
`160` Pa-s