The terminal velocity of a copper ball of radius 2.0 mm falling through a tank of oil at 20^@C is 6.5 cm s^-1. Compute the viscosity of the oil at 20^@C. Density of oil is 1.5 times 10^3kg m^-3.density of copper is 8.9 times 10^3 kg m^-3.

The terminal velocity of a copper ball of radius 2.0 mm falling throug

1.	The terminal velocity of a copper ball of radius 2.0 mm falling through a tank of oil at 20^@C is 6.5 cm s^-1. Compute the viscosity of the oil at 20^@C. Density of oil is 1.5 times 10^3kg m^-3.density of copper is 8.9 times 10^3 kg m^-3.
Answer» SOLUTION :We have `v_1=6.5 TIMES 10^2 ms^-1,a=2 times 10^3m ` `g=9.8 ms^-2,p=8.9 times 10^3 KG m^-3` `sigma=1.5 times 10^3 kg m^-3`. From EQ. (10.20) `eta=2/9 times ((2 times 10^-3)^2 m^2 times 9.8 ms^-2)/(6.5 times 10^-2 ms^-1) times 7.4 times 10^3 kg m^-3` `=9.9 times 10^-1 kg m^-1 s^-1`