Thermodynamics Conceptual Question

[boeing9379]

Homework Statement

I have a system with air flowing through a ducting with two inlets and one exit operating at steady state. There is no heat transfer or potential energy change. I know the mass flow rates and velocities at all inlets and exits. How would I go about finding the rate of change in kinetic energy for the stream flowing from point 2, an inlet, to point 3, the outlet.

Homework Equations

The Attempt at a Solution

I don't know exactly what the rate of change of kinetic energy between one of the inlets and the exit means, so I don't know where to start.

 

[crims0ned]

Maybe the rate of change in the kinetic energies of the inlets and outlet per minute or second? K.E. = \frac{1}{2}mv^2

 

[rock.freak667]

Adding to what crims0ned suggested

\frac{d}{dt}(KE) = \frac{1}{2} \dot{m}v^2