Two equal drops of water are falling through air with a steady velocity v. If the drops coalesced, what will be the new velocity?

Explanation

`(4)/(3)piR^(3)xxrho=(4)/(3)pir^(3)xxrho+(4)/(3)pir^(3)xxrho`
or `R=(2^((1)/(3)))r` and `v_(t)alphar^(2)` (stokes now)
`(v^(1))/(v)=(R^(2))/(r^(2))=2^(2//3)`
`:. v^(1)=2^(2//3)`