A triangular channel $($n $=0\mathrm{.}012)$ with a side slope of $1\mathrm{.}5$ carries $30$ cfs$.$ Classify the channel bed slope if the channel is laid on a physical slope of:

$(1)0\mathrm{.}001$

$(2)0\mathrm{.}005$

answers: $(1)2\mathrm{.}30$ ft; $(2)1\mathrm{.}87$ ft

$(3)1\mathrm{.}38$ ft