Physics

Problem

A horizontal pipeline first contracts from a diameter of

12\,\text{cm}

6\,\text{cm}

and then immediately expands to

9\,\text{cm}

. The speed of water in the

12\,\text{cm}

section is

2\,\text{m\,s}^{-1}

. Which pair of speeds

(v_2, v_3)

in the

6\,\text{cm}

and

9\,\text{cm}

sections, respectively, is correct? a)

(8.0\,\text{m\,s}^{-1},\;3.6\,\text{m\,s}^{-1})

(4.0\,\text{m\,s}^{-1},\;2.7\,\text{m\,s}^{-1})

(8.0\,\text{m\,s}^{-1},\;1.8\,\text{m\,s}^{-1})

(4.0\,\text{m\,s}^{-1},\;3.6\,\text{m\,s}^{-1})