Question

The cylindrical tube of a spray pump has radius R, one end of which has n fine holes, each of radius r. If the speed of the liquid in the tube is V, the speed of the ejection of the liquid through the holes is:

• A. $\frac{V{R}^2}{n^3{r}^2}$
• B. $\frac{V{R}^2}{nr}$
• C. $\frac{V{R}^2}{n^2{r}^2}$
• D. $\frac{V{R}^2}{n{r}^2}$

Answer 1

The correct option is D

$\frac{V{R}^2}{n{r}^2}$

Apply equation of continuity

$A_1{v}_1=A_2{v}_2$

$\pi R^{2}V=n\pi r^{2}u$

$u=\frac{V{R}^2}{n{r}^2}$