A rigid spherical particle undergoes free settling in a liquid of density $750$ kg$/$m$3$ and viscosity $9\mathrm{.}81$x$10-3$ Pa$.$s$.$ Density of the particle is $3000$ kg$/$m$3$ and the particle diameter is $2$x$10-4$ m$.$ Acceleration due to gravity is $9\mathrm{.}81$ m$/$s$2.$ What will be the terminal velocity of the particle? Also, calculate the time required for the particle to settle in a tank of $0\mathrm{.}25$ m height.