The answer is provided. I need the work for how to get the corrct answer

Hydrodynamio flow through a porous diaphragm Consider the hydrodonamie flow of nitrogen at 400K through the porous iragm described in Brample 1.24. It is desired to achieve a superficial gas to through the diaphragm of 0.28kg of Nz2m2 s by increasing the upstream ure while maintaining the downstream pressure constant at 0.1atm. alate the upstream pressure roquired. Answer: 18.64kPa