Question

water flows through a tube as shown in the figure. find the difference in mercury level if the speed of flow of water at point Ais 2m/s and at point Bis 5m/s(g=9.8m/s)
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Answer 1

Water flows through the tube as shown in figure. The areas of cross-section of the wide and the narrow portions of the tube are 5cm2 and 2cm2 respectively. The rate of flow of water through the tube is 500cm3/s. Find the difference of mercury levels in the U-tube.

ANSWER

A1v1=A2v2=rate of flow of water

5v1=2v2=500 cm3/s

∴   v1=100 cm/s=1.0 m/s

v2=250 cm/s=2.5 m/s

21ρw(v22−v12)=ρHgghHg

∴   hHg=2ρHggρw(v