AP EAMCET201823 Apr 2018Evening ShiftPhysicsMechanical Properties of FluidsActual
Two solid sphere of radii 2 ~mm and 4 ~mm are tied to the two ends of a light string and released in a liquid of specific gravity 1.3 and coefficient of viscosity 1 ~Pa -s. The string is just taut, when the two spheres are completely in the liquid. If the density of the materials of the two sphere is 2800 kgm ⁻³ , then the terminal velocity of the system of the sphere is (take, g=10 ~ms ⁻² )
Options
- A2 cms ⁻¹
- B4 cms ⁻¹
- C4 ~ms ⁻¹
- D2 ~ms ⁻¹
Correct answer
B. 4 cms ⁻¹
Step-by-step solution
Free body diagram of system is When system achieves terminal velocity, gathered F_ net =0 4 3 _f g (r_ A ^3+r_ B ^3 )+6 v (r_A+r_B )= (m_A+m_B ) g gathered With values, we get v=4 cms ⁻¹