Q$4$ Weight flow is defined as $W^{}=Q,$ and mass flow is defined as $m^{}=Q.$ If the weight flow

is $400lb\frac{f}{s}$ and the specific weight of water is $62\mathrm{.}4lb\frac{f}{f}{t}^3,$ what is the average velocity of water

flowing through a rectangular duct that is $30$ cm wide and $20$ cm high $(20$ points$).$

$($a$)4\mathrm{.}38\frac{m}{s}$

$($b$)3\mathrm{.}03\frac{m}{s}$

$($c$)0\mathrm{.}227\frac{m}{s}$

$($d$)8\mathrm{.}01\frac{m}{s}$