Homework help

[mnemosyne]

I'm hoping someone here can help me out with a homework related dilemma I have. I have an assignment for my Fluid dynamics class, on frictional flows through constant-area pipes (Fanno flow), and I'm not sure how to proceed past this little obstacle.

See, there's a cat on my lap, and she's sleeping, and she clearly doesn't want me to move, so I can't reach my pen and paper.

Anyone have any advice?