Two drops of equal radius are falling through air with a steady velocity of 5cm/sec . If the drops coalesce then its term I all velocity will be

According to Stoke''s Law, terminal Vel is proportional radius.

When drops coalesce, the final radius, r'' = r.2^(1/3) [Conserve volume to derive this result.]

So final terminal vel. = 5.2^(1/3)

5cm/sec

The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress. For liquids, it corresponds to the informal notion of "thickness". For example, honey has a higher viscosity than water.^[1]

according to stoke`s law velocity is proportional to radius ^2. conserve volume : radius of coalesced drop is 2^1/3 each drop. therefore answer is 5 cm/s X 2^2/3