1. The problem statement, all variables and given/known data . Air, at a flow rate of 30 [N/s], flows through the reducer shown below. In the 300 [mm] diameter section of the pipe the specific weight of the air is 9.8 [N/m3 ]. When flowing through the reducer the pressure and temperature will fall causing the air to expand and producing a reduction of density. The specific weight in the 200 [mm] diameter section of the pipe is 7.85 [N/m3 ]. Find the volumetric flow rates and average velocities in both sections of the pipe. 2. Relevant equations 3. The attempt at a solution Ok, so I'm a little confused on what the flow rate of 30 N/s is! I've never seen that combination of units before. Can I divide it by gravity to get the mass flow rate? When the problem asks for average velocity at inlet and exit, is this a different formula than this one? mass=Area*velocity*density Also, is this flow moving from right to left?