Two metal spheres are falling through a liquid of density  2×103kg/m3 with the same terminal speed. The material density of sphere 1 and sphere 2 are 8×103kg/m3   and   11×103kg/m3  respectively. The ratio of their radii is:

The terminal velocity of the spherical body of radius R, density ρ  falling through a liquid of density σ  is given by:υT=29R2ρ−σgηor    R12R22=ρ2−σρ1−σSubstituting the given values, we get; R12R22=(11×103−2×103)(8×103−2×103)=96=32R1R2=32