A small metal ball falls in liquid with a terminal velocity of V. If a ball of radius twice of first ball but same mass falls through a same medium, calculate the terminal velocity with which it falls.

A small metal ball falls in liquid with a terminal velocity of V. If a

1.	A small metal ball falls in liquid with a terminal velocity of V. If a ball of radius twice of first ball but same mass falls through a same medium, calculate the terminal velocity with which it falls.
Answer» Solution :Given`v = (2R^(2)rhog)/(9eta)` mass `= 3/4 pi r^(3) RHO = 4/3 pi (2r)^(3)rho_(1)`or`rho_(1) = (rho)/(8)` TERMINAL velocity of second ball is `v_(1) = (2(2r)^(2)(rho/8)G)/(9eta) = v/2` `v_(1) = v/2`