Utilizing all the data in Chapter $12,$ Problem #$1$ on page $288$ of your text with the exception of A $24-$inch RCP outfall discharges directly onto the ground. The pipe has a

slope of $1\mathrm{.}75$ percent and $n-$value of $0\mathrm{.}015$ and carries a design discharge of $20.$

cfs$.$ Design a riprap apron for the outfall.

the discharge $($use $25cfs$ instead of $20cfs),$ please design the requested rip$-$rap apron.

a$.$ What is $d_{50}$ for the stone size? $(10$ points$)$A $24-$inch RCP outfall discharges directly onto the ground. The pipe has a

slope of $1\mathrm{.}75$ percent and $n-$value of $0\mathrm{.}015$ and carries a design discharge of $20.$

cfs$.$ Design a riprap apron for the outfall.

b$.$ What is $L_a?(10$ points$)$

c$.$ What is W $?(10$ points$)$