Question

A cylinder of height $20m$ is completely filled with water. The velocity of efflux of water ( in $m{s}^{-1}$) through a small hole on the side wall of the cylinder near its bottom, is-

• A. $10$
• B. $20$
• C. $25.5$
• D. $5$

Answer 1

The correct option is B $20$

Applying Bervoulli's theorem at $\left(1\right)$ & $\left(2\right)$

$\frac{P_1}{pg}+\frac{V_1^2}{2g}+h_1$

$=\frac{P^2}{Pg}+\frac{V_2^2}{2g}+h_2$

$P_1=P_2$ & $V_1=0$

Thus, $V_2^2=2g(h_1-h_2)$

$V_2^2=2\left(10\right)\left(20\right)$

$V_2=20$ m/s.