When a metallic sphere falls through castor oil, its velocity become uniform, called terminal velocity. The terminal velocity of a copper ball of radius 2 mm falling through a tank of oil at 20^@C is 6.5 cm/s. Compute the viscosity of the oil at 20^@. Density of oil is 1.5xx10^3kg//m^3.

When a metallic sphere falls through castor oil, its velocity become u

1.	When a metallic sphere falls through castor oil, its velocity become uniform, called terminal velocity. The terminal velocity of a copper ball of radius 2 mm falling through a tank of oil at 20^@C is 6.5 cm/s. Compute the viscosity of the oil at 20^@. Density of oil is 1.5xx10^3kg//m^3.
Answer» SOLUTION :`a=2xx10^-3m, v=6.5xx10^-2ms^-1, rho=8.9xx10^3kgm^-3` `sigma=1.5xx10^3kgm^-3, ETA` = ? `v=2/9 (a^2(rho-sigma))/eta G` `v=2/9 (a^2(rho-sigma))/eta g = 2/9 ((2xx10^-3)^2 (8.9xx10^3-1.5xx10^3)9.8)/(6.5xx10^-2)=0.99 kgm^-1s^-1`