Mechanical Properties Of Fluids Question 9

Question 9 - 01 February - Shift 2

The surface of water in a water tank of cross section area $750 cm^{2}$ on the top of a house is $h m$. above the tap level. The speed of water coming out through the tap of cross section area $500 mm^{2}$ is $30 cm / s$. At that instant, $\frac{d h}{d t}$ is $x \times 10^{-3} m / s$. The value of $x$ will be

Show Answer

Answer: (2)

Solution:

Formula: Equation of Continuity

$A_1 V_1=A_2 V_2$

$750 \times 10^{-4} V_1=500 \times 10^{-6} \times 0.3$

$V_1=\frac{500 \times 3 \times 10^{-3}}{750} m / s$

$=2 \times 10^{-3} m / s$

$dh$

$=-2 \times 10^{-3} m / s$