InterviewSolution
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InterviewSolution
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Two indetical spherical drops of water are falling (vertically downwards) through air with a steady velocity of `5(cm)/(sec)`. If both the drops coalesce (combine) to form a new spherical drop, the terminal velocity of the new drop will be (neglect buoyant force on the drops.)A. `5xx2(cm)/(sec)`B. `5xxsqrt2(cm)/(sec)`C. `5xx(4)^((1)/(3))(cm)/(sec)`D. `(5)/(sqrt2)(cm)/(sec)` |
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Answer» Correct Answer - C When two drops of radius `r` each combine to form a big drop, the radius of big drop will be given by `(4)/(3)piR^3=(4pi)/(3)r^2+(4pi)/(3)r^3` or `R^3=2r^2` or `R=2^((1)/(3))r` Now `(V_R)/(V_r)=((R )/(R ))^2=2^((2)/(3))=4^((1)/(3))` `V_R=5xx4^((1)/(3))(cm)/(s)` |
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