InterviewSolution
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InterviewSolution
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If n equal rain droplets falling through air with equal steady velocity of `10 cm s^(-1)` coalesce, find the terminal velocity of big drop formed. |
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Answer» Let, R be the radius of each droplet and big drop respectively. Volume of big drop = n x volume of a small droplet `(4)/(3) pi R^(3) =nxx(4)/(3)pi r^(3)` or `R=n^(1//3)r` Terminal velocity of small droplet, `v=(2r^(2)(rho-sigma)g)/(9eta)` Terminal velocity of big drop, `V=(2R^(2)(rho-sigma)g)/(9eta)` Dividing (ii) by (i), we get `(V)/(v)=(R^(2))/(r^(2))=(n^(1//3)r^(2))/(r^2)=n^(2//3)` or `V=n^(2//3) v cm//s` |
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