Question

Water is moving with a speed of 5.18 $ m{{s}^{-1}} $ through a pipe with a cross-sectional area of 4.20 $ c{{m}^{2}} $ . The water gradually descends 9.66 m as the pipe increase in area to 7.60 $ c{{m}^{2}} $ . The speed of flow at the lower level is

• A. 3.0 $ m{{s}^{-1}} $
• B. 5.7 $ m{{s}^{-1}} $
• C. 3.82 $ m{{s}^{-1}} $
• D. 2.86 $ m{{s}^{-1}} $

Answer 1

Answer: (D)

$ {{a}_{1}}{{v}_{1}}={{a}_{2}}{{v}_{2}} $
$ \Rightarrow $ $ 4.20\times 5.18=7.60\times {{v}_{2}} $
$ \Rightarrow $ $ {{v}_{2}}=2.86\,\,m/s $