Question

A metallic ball of diameter $2.1\times 10^{-3}m$ drops in fluid of sp. gravity 0.96 and viscosity 16 Poise. The density of metallic ball is $12010kg/m^{3}$.

Answer 1

Given, diameter of the ball d= 2.1×10⁻³m

radius, r= 1.05×10⁻³m

Volume of the ball, V= (4/3)πr³= 4.85×10⁻⁹m³

We know, density,

ρ= m/V

 So its mass is, m=  ρV

                             = 12010 × 4.85×10⁻⁹

                             = 5.85×10⁻⁵ kg