Fluid Mechanics Viscosity Question 310
Question: A rain drop of radius 0.3mm falling vertically downwards in air has a terminal velocity of 1 m/ s. The viscosity of air is$ 18\times {{10}^{-5}}poise $ . The viscous force on the drop is
Options:
A) $ 101.73\times {{10}^{-4}}dyne $
B) $ 101.73\times {{10}^{-5}}dyne $
C) $ 16.95\times {{10}^{-5}}dyne $
D) $ 16.95\times {{10}^{-4}}dyne $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Viscous force$ =6\pi \eta rv $ $ =6\pi \times 18\times {{10}^{-5}}\times 0.03\times 100 $ $ =101.73\times {{10}^{-4}}dyne $
BETA
