JEE Mains · Physics · STD 11 - 9.1 fluid mechanics
Small water droplets of radius \(0.01 \mathrm{~mm}\) are formed in the upper atmosphere and falling with a terminal velocity of \(10 \mathrm{~cm} / \mathrm{s}\). Due to condensation, if \(8 \mathrm{such}\) droplets are coalesced and formed a larger drop, the new terminal velocity will be _______ \(\mathrm{cm} / \mathrm{s}\).
- A \(20\)
- B \(40\)
- C \(50\)
- D \(70\)
Answer & Solution
Correct Answer
(B) \(40\)
Step-by-step Solution
Detailed explanation
\(\mathrm{m}=\text { mass of small drop }\) \(\mathrm{M}=\text { mass of bigger drop }\) \(\mathrm{V}_{\mathrm{t}}=\frac{2}{9} \frac{\mathrm{R}^2(\rho-\sigma) \mathrm{g}}{\eta}\) \(8 \propto \mathrm{m}=\mathrm{M}\)…
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