Spherical Particles of Density 1

Multiple Choice

Spherical particles of density 1.8 g/cm³ are shaken in a container of water (viscosity = 1.0 × 10−³ N⋅s/m³) .The water is 9.0 cm deep and is allowed to stand for 30 minutes.What is the radius of the largest particles still in suspension at that time?

A) 2.5E-6 m
B) 6.4E-6 m
C) 5.4E-6 m
D) 1.8E-6 m
E) 4.1E-6 m