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^(-1). Computethe viscosity of the oil at 20^@ C . Density of oil =1.5 xx 10^(3) kg m^(-3) density of copper is 8.9 xx 10^(3) kg m^(-3).

The terminal velocity of a copper ball of radius 2 mm falling through

1.	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^(-1). Computethe viscosity of the oil at 20^@ C . Density of oil =1.5 xx 10^(3) kg m^(-3) density of copper is 8.9 xx 10^(3) kg m^(-3).
Answer» SOLUTION :`eta = 2/9 (r^2)/V(rho - rho.) g = (2 xx (2 xx 10^(-3))^(2) xx (8.9 xx 10^3 - 1.5 xx 10^3) xx 9.8)/(9 xx 6.5 xx 10^(-2))` `eta = 0.992` DECAPOISE