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JEE Mains · Physics · STD 11 - 9.1 fluid mechanics
In an experiment, a small steel ball falls through a Iiquid at a constant speed of \(10\, cm/s\). If the steel ball is pulled upward with a force equal to twice its effective weight, how fast will it move upward ? ......... \(cm/s\)
- A \(5\)
- B \(0\)
- C \(10\)
- D \(20\)
Answer & Solution
Correct Answer
(C) \(10\)
Step-by-step Solution
Detailed explanation
Weight of the body \(W = mg = \frac{4}{3}\pi {r^3}\rho g\) \(T = \frac{4}{3}\pi {r^3}\sigma g\) \(and\,F = 6\pi \eta vr\) When the body attains terminal velocity net force acting on the body is zero \(i.e.,\) \(W - T - F = 0\) And terminal velocity…
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