NEET2022PhysicsMechanical Properties of FluidsActual
The terminal velocity of a copper ball of radius 5 ~mm falling through a tank of oil at room temperature is 10 ~cm ~s ⁻¹ . If the viscosity of oil at room temperature is 0.9 ~kg ~m ⁻¹ ~s ⁻¹ , the viscous drag force is:
Options
- A8.48 10⁻³ ~N
- B8.48 10⁻⁵ ~N
- C4.23 10⁻³ ~N
- D4.23 10⁻⁶ ~N
Correct answer
A. 8.48 10⁻³ ~N
Step-by-step solution
By Stobal's law, F =6 r v (where, the symbols have their usual meanings) aligned F & =6 3.14 0.9 5 10⁻³ 10 10⁻² ~F & =84.78 10⁻⁴ & =8.478 10⁻³ ~N =8.48 10⁻³ ~N aligned