a$)$ An above$-$ground flume, built from timber, is to convey water from a

$(5$ marks$)$

mountain lake to a small hydroelectric plant. The flume is to deliver water

at $Q=2\frac{m^3}{s}$; the slope is $S_0=0\mathrm{.}002$ and $n=0\mathrm{.}013.$ Evaluate the required

flume size for $($a$)$ a rectangular section with $\frac{y}{b}=0\mathrm{.}5$ and $($b$)$ an equilateral

triangular section.

$Q=Av=A\frac{1}{n}{R}^{\frac{2}{3}}{S}_0^{\frac{1}{2}}$