Water is flowing through a tube of nonuniform cross-section. Ratio of the radius at entry and exit end of the pipe is `3:2.` Then the ratio of velocities at entry and exit of liquid is

Options

A. `4:9`
B. `9:4`
C. `8:27`
D. `1:1`

Answer

A

Explanation

If velocities of water at entry and exit point are `v_(1) and v_(2)`, then according to equation of continuity.
`A_(1) v_(1)= A_(2) v_(2) rArr (v_(1))/(v_(2))= (A_(2))/(A_(1))= ((r_(2))/(r_(1)))^(2) = ((2)/(3))^(2)= (4)/(9)`