Question

A hole is in the bottom of the tank having water. If total pressure at the bottom is $3$ atm $(1atm=10^{5}N{m}^{-2})$, then velocity of water flowing from hole is

• A. $\sqrt{400}m{s}^{-1}$
• B. $\sqrt{600}m{s}^{-1}$
• C. $\sqrt{60}m{s}^{-1}$
• D. none of these

Answer 1

Answer: (A)

Total pressure $(P)$ = atmospheric pressure $(P_0)$ + pressure due to water columnn $p$'
$P=P_0+P^{\prime }$
$\therefore P^{\prime }=P-P_0=3-1=2$ atm
or, $\rho gh=2$ atm or, $h\times 10\times 10^3=2\times 10^5$
or, $h=20m$
Velocity of water coming from hole is
$v=\sqrt{2gh}=\sqrt{2\times 10\times 20}$
$=\sqrt{400}m{s}^{-1}$