Question

Water is moving with a speed of 5.18 ms${}^{-}1$ 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

The correct option is D

2.86 $m{s}^{-1}$

$a_1{v}_1=a_2{v}_2$

$\Rightarrow 4.20\times 5.18=7.60\times v_2\Rightarrow v_2=2.86m/s$