Neglecting the density of air, the terminal velocity obtained by a raindrop of radius 0.3 ~mm falling through air of viscosity 18 10⁻⁵ ~N ~s ~m ⁻² will be

Step-by-step solution

The terminal velocity of the spherical raindrop of radius r is given by v_t= 2 r^2 g 9 where is the density of water and the viscosity of air. Substituting r=0.3 ~mm =0.3 10⁻³ ~m , =10^3 ~kg / m ^3, g=9.8 ~m / s ^2 and =1.8 10⁻⁵ ~N ~s / m ^2 , we get aligned & v_t= 2 (0.3)^2 10⁻³ 9.8 9 1.8 10⁻⁵ & =10.9 ~m ~s ⁻¹ aligned