CH ENGR 101A Quiz: 2017 Homework 3 Solutions
Document Summary
A classroom contains dust of uniform concentration c = dust . It is to be cleaned up by introducing fresh air at velocity vi through a duct of area ai on one wall and exhausting the room air at velocity v0 through a duct a0 on the opposite wall. Find an expression for the instantaneous rate of change of dust mass dm dust dt within the room. A water jet of velocity vj impinges normal to a flat plate which moves to the right at velocity vc. Find the force required to keep the plate moving at constant velocity if the jet density is 1000 kg/m3, the jet area is 3 cm2, and vj and vc are 20 and 15 m/s, respectively. Neglect the weight of the jet and plate, and assume steady flow with respect to the moving plate with the jet splitting into an equal upward and downward half-jet.
