Question

A hole is made at the bottom of the tank filled with water (density $1000kg/m^3$), If the total pressure at the bottom ofthe tankis 3 atmosphere
( 1 atmosphere = ${10}^{5}N/m^2$ ), 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

The correct option is B $\sqrt{400}m/s$

We know that velocity of efflux,

$v=\sqrt{2gh}$

At the bottom of tank pressure is 3 atmosphere. So, total pressure due to water column

$h\rho g=2\times {10}^5$

$gh=2\times {10}^2$

$v=\sqrt{2gh}=\sqrt{2\times 2\times {10}^2}=\sqrt{400}m/s$