Question

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 x 103 kg/m3, diameter 2.0 mm) is dropped in a container of motor oil. It takes 11 s to fall a distance of 0.65 m. Calculate the viscosity (in kg/(m.s)) of the oil. 0.291 kg/(m.s)

Answer 1

The Now Given data are d = 0.65m t = ll see. we know that - The Terminal velocity ve = put the values ve 0:65 = The Mapy o.osgog m/s Thon - v=3 malby 47 put The values m =(7.8 %103Jx[**T fo=3967210kg Now velocity are the 2X20-037 mg - Velocity (V) = GIVE put the vale. - V > 3.9267x10 xgis 7xTXTঘনত্যেভ০৭ V = 0.287 kg/m's