Question

A hole is made at the bottom of the tank filled with water (density $\text{1000}\text{kg/}{\text{m}}^{\text{3}}$ ). If the total pressure at the bottom of the tank is 3 atmosphere (1 atmosphere $\text{=1}{\text{0}}^{\text{5}}\text{N/}{\text{m}}^{\text{2}}$ ), then the velocity of efflux is

• A. $\sqrt{200}m/s$
• B. $\sqrt{400}m/s$
• C. $\sqrt{500}m/s$
• D. $\sqrt{800}m/s$

Answer 1

Answer: (B)

Applying Bernoullis theorem
$p_1+0+\rho gH=p_2+\frac{1}{2}\rho v^2+\rho gH$
$p_1-p_2=\frac{1}{2}\rho v^2$
$3\times {10}^5-1\times {10}^5=\frac{1}{2}\rho v^2$
$2\times {10}^5=\frac{1}{2}\rho v^2$
$2\times {10}^5=\frac{1}{2}\times {10}^3\times v^2$
$v^2=400$
$v=\sqrt{400}$