PYQ NEET- Thermal Properties Of Matter L-6

Question: The terminal velocity of a copper ball of radius $5 \mathrm{~mm}$ falling through a tank of oil at room temperature is $10 \mathrm{~cm} \mathrm{~s}^{-1}$. If the viscosity of oil at room temperature is $0.9 \mathrm{~kg} \mathrm{~m}^{-1} \mathrm{~s}^{-1}$, the viscous drag force is :#

A) $4.23 \times 10^{-6} \mathrm{~N}$

B) $8.48 \times 10^{-3} \mathrm{~N}$

C) $8.48 \times 10^{-5} \mathrm{~N}$

D) $4.23 \times 10^{-3} \mathrm{~N}$

Answer: $8.48 \times 10^{-3} \mathrm{~N}$#