JEE Mains · Physics · STD 11 - 9.1 fluid mechanics
Sixty four rain drops of radius 1 mm each falling down with a terminal velocity of \(10 cm / s\) coalesce to form a bigger drop. The terminal velocity of bigger drop is _________ \(cm / s\).
- A 120
- B 80
- C 160
- D 40
Answer & Solution
Correct Answer
(C) 160
Step-by-step Solution
Detailed explanation
\(V _{ T }=\frac{2 r ^2 g}{9 n }[\sigma-\rho]\) \(V _{ T } \propto r ^2\) 64 drop \(64\left(\frac{4}{3} \pi R_1^3\right)=\frac{4}{3} \pi R_2^3\) \(R _2=4 R _1\)…
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