Question 291: Properties of Matter

Question

The diameter of an air bubble which was initially $$2 \mathrm{~mm}$$, rises steadily through a solution of density $$1750 \mathrm{~kg} \mathrm{~m}^{-3}$$ at the rate of $$0.35 \,\mathrm{cms}^{-1}$$. The coefficient of viscosity of the solution is _________ poise (in nearest integer). (the density of air is negligible).

Accepted Answer

$$F = 6\pi \eta rv$$
$${4 \over 3}\pi {r^3}{ho _l}g = 6\pi \eta rv$$
$$\eta  = {{2{r^2}{ho _l}g} \over v}$$
$$ = {{2 	imes {{(2 	imes {{10}^{ - 3}})}^2} 	imes 1750 	imes 10} \over {9 	imes 3.5 	imes {{10}^{ - 3}} 	imes 4}}$$
$$ = 11$$ poise

Properties of Matter

Integer / Numeric Answer Type