Question

27 equal drops of liquid are falling through air with steady velocity v, for each. If the drops are coalesced then new velocity of bigger drop is
1) 3 v
2) 9v
3) v
4) 27 v​

Answer 1

Answer:

9v

Explanation:

terminal velocity is directly proportional to square of radius of body

so,

then the ratio of terminal velocity of small drop is equal to terminal velocity of big drop

v : V = r^2 : R^2 - a

also,

vol. of 27 small drop = vol. of big drop

27×4/3 pie r^3 = 4/3 pie R^3

27×r^3 = R^3

R = 3 r

now put in a we get

v:V=r^2:9r^2

V = 9v ans.