$($ii$)$ An oil $($specific gravity $0\mathrm{.}83$ and viscosity $0\mathrm{.}08k\frac{g}{m}s)$ passes through a pipe of $12$ mm diameter with a maximum velocity of $4\mathrm{.}6\frac{m}{s}.$ Determine $($a$)$ Reynolds number, $($b$)$ mass flow rate in $k\frac{g}{s},($c$)$ friction coefficient $f,$ and $($d$)$ pressure gradient along the pipe.

$(1+5+4)+10$