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