A bubble of air of diameter 0.2 cm rises up uniformly in water with a velocity of `200cm//s` . If the density of water is `1gcm^(-3)` , find coefficient of viscosity of water. Neglect density of air w.r.t that of water.`(g=9.8m//s^(2))`

Explanation

`r=(d)/(2)=(0.2)/(2)=0.1cm,v_(t)=-200cm//s`
Bubble moves upward so it is taken negative
`rho_(o)=1(g)/(cm^(3))`
`rho=0,eta=?`
`v_(t)=(2)/(9)(r^(2)g)/(eta)(rho-rho_(o))`
`thereforeeta=(2)/(9)(r^(2)g)/(v_(t))(rho-rho_(0))`
`thereforeeta=(2)/(9)(r^(2)g)/(v_(t))(rho-rho_(0))`
`=10.9xx10^(-3)`
`=0.0109` poise