Fluid Mechanics

While determining the coefficient of viscosity of the given liquid, a spherical steel ball sinks by a distance $\mathrm{h}=0.9 \mathrm{~m}$. The radius of the ball $\mathrm{r}=\sqrt{3} \times 10^{-3} \mathrm{~m}$. The time taken by the ball to sink in three trails are tabulated as follows.

$$ \begin{array}{|l|l|} \hline \text { Trial No. } & \text { Time taken by the ball to fall by } \mathrm{h} \text { (in second) } \\ \hline 1 . & 2.75 \\ \hline 2 . & 2.65 \\ \hline 3 . & 2.70 \\ \hline \end{array} $$

The difference between the densities of the steel ball and the liquid is $7000 \mathrm{~kg} \mathrm{~m}^{-3}$. If $\mathrm{g}=10 \mathrm{~ms}^{-2}$, then the coefficient of viscosity of the given liquid at room temperature is