# Biomedical Eng. HW Prob! Help!

1. Sep 19, 2009

### sixers786

***Biomedical Eng. HW Prob! Help!***

1. The problem statement, all variables and given/known data
http://img11.imageshack.us/img11/3586/20582546.jpg [Broken]

2. Relevant equations

3. The attempt at a solution

all i know is the the sum of flow rate in is equal to the sum of flow rate out
so i did
0.1 mg/ml * 1200 ml/min = 1.5 ml/min*5 mg/ml + mass flow rate blood.
and the m flow rate for blood is equal to 112.5 mg/min
i really don't know what to do next..plz help.

Last edited by a moderator: May 4, 2017
2. Sep 19, 2009

### sixers786

Re: ***Biomedical Eng. HW Prob! Help!***

3. Sep 22, 2009

### burningbend

Re: ***Biomedical Eng. HW Prob! Help!***

first do an overall mass balance

Vb=Vf+Vu

then do your component balances

cu,bVb=cu,fVf+cu,uVu
cd,bVb=cd,fVf+cd,uVu

here you only have 3 unknowns. plug and chug, but make sure your units match up since some of your givens are funky.

4. Sep 23, 2009

### burningbend

Re: ***Biomedical Eng. HW Prob! Help!***

one other thing to note in this problem is that we're not really doing a mass balance, but a volumetric flow balance. you can ONLY do volumetric flow balances when your density is constant, otherwise you must convert each stream into a mass flow rate!