A simple viscometer measures the time t taken by a solid sphere to fall a distance L through a test fluid of density p. The fluid viscosity is then given by Wood ift 3DL 2pDL where D is the sphere diameter and Wnet is the sphere net weight in the fluid. Assume that a 2.9 mm diameter aluminum sphere (density 2700 kg/m) falls in an oil of density 875 kg/m3. Estimate the viscosity of the oil if the time taken to fall 50 cm is 32 s. 1kg/[m.s)