Question

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 ____

Answer 1

The correct answer is 2.
A1​V1​=A2​V2​
750×10−4V1​=500×10−6×0.3
V1​=750500×3×10−3​m/s
=2×10−3m/s
dtdh​=−2×10−3m/s