A spherical ball of radius 1 mm and density 10 . 5 g cc - 1 is dropped in glycerine of coefficient of viscosity 9 . 8 poise and density 1 . 5 g cc - 1 . Viscous force on the ball when it attains constant velocity is 3696 × 10 - x N . The value of x is (Given, g = 9 . 8 m s - 2 and π = 22 7 )

Step-by-step solution

Viscous force on the ball when it attains constant velocity i.e., terminal velocity is, F v = m g - F B     As ,   a = 0 Here, F B is buoyant force. ⇒ F v = V ρ b g - V ρ g g = V g ρ b - ρ g = 4 3 π 10 - 3 3 × 9 . 8 10 . 5 - 1 . 5 × 10 3 ≈ 3696 × 10 - 7   N Thus, x = 7 .