A sanding operation injects 105 particles/s into the air in a room as shown in Fig. P4.8...

A sanding operation injects 10⁵ particles/s into the air in a room as shown in Fig. P4.8R. The amount of dust in the room is maintained at a constant level by a ventilating fan that draws clean air into the room at section (1) and expels dusty air at section (2). Consider a control volume whose surface is the interior surface of the room (excluding the sander) and a system consisting of the material within the control volume at time (a) If N is the number of particles, discuss the physical meaning of and evaluate the terms (b) Use the Reynolds transport theorem to determine the concentration of particles in the exhaust air for steady-state conditions.