Question

The pressure in a water pipe on the second floor of a building is $60,000Pa$ and on the third floor it is $30,000Pa$. Find the height of the first floor (in m)

(Density of water $=1000kg$ $m^{-3}$, $g=10m$ $s^{-2}$)

Answer 1

Pressure at $2^{nd}$ floor, $P_2$ = 60000 $P_a$

Pressure at $3^{rd}$ floor, $P_3$ = 30000 $P_a$

So $P_2=P_3+\varrho gh$

60000 = 30000 + $\varrho gh$

30000 = $\varrho gh$ = ${10}^3\times 10\times h$

$h=3m$