A natural gas is flowing through a $1m$ diameter and $6\mathrm{.}5km$ long pipeline $($friction factor $=0\mathrm{.}0024)$ at a constant temperature of $15C.$ The pressure at the inlet of the pipe is $5\mathrm{.}7$MPa. What is the maximum mass flow rate of the gas that can be achieved and the corresponding downstream pressure?

$[$Ans$.G_{\text{m}\text{a}\text{x}}=1012\mathrm{.}3kg{s}^{-1},P_w=498\mathrm{.}6$kPa $]$ CAN I GET A DIFFERENT SOLUTION NOT THE ONE UPLOADED BEFORE AS I DIDNT UNDERSTAND IT $,$ i need step by step solution $,$ thank you$($: