Stokes’ law describes sedimentation of particles in liquids and can be used to measure viscosity. particles in liquids achieve terminal velocity quickly. one can measure the time it takes for a particle to fall a certain distance and then use stokes’ law to calculate the viscosity of the liquid. suppose a steel ball bearing (density 7.8×103 kg/m3, diameter 3.0 mm) is dropped in a container of motor oil. it takes 12 seconds to fall a distance of 0.60 m. calculate the viscosity of the oil.