Q.

The surface of water in a water tank of cross-sectional area 750 cm2 on the top of a house is h m above the tap level. The speed of water coming out through the tap of cross-sectional area 500 mm2 is 30 cm/s.  At that instant, dhdt is x×10-3 m/s. The value of x will be _______.             [2023]


Ans.

(2)

a1v1=a2v2

750×10-4v1=500×10-6×0.3

v1=500×3×10-3750m/s=2×10-3 m/s

dhdt=-2×10-3 m/s