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).
Answer (integer)
11
Solution
<p>$F = 6\pi \eta rv$</p>
<p>${4 \over 3}\pi {r^3}{\rho _l}g = 6\pi \eta rv$</p>
<p>$\eta = {{2{r^2}{\rho _l}g} \over v}$</p>
<p>$$ = {{2 \times {{(2 \times {{10}^{ - 3}})}^2} \times 1750 \times 10} \over {9 \times 3.5 \times {{10}^{ - 3}} \times 4}}$$</p>
<p>$= 11$ poise</p>
About this question
Subject: Physics · Chapter: Properties of Solids and Liquids · Topic: Elasticity
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