A 19000 cubic foot room initially has a radon level of 870 picocuries per cubic foot. A ventilation system is installed that brings in 500 cubic feet of air per hour that contains 7 picocuries per cubic foot, while an equal quantity of the well-mixed air in the room leaves the room each hour. Setup and use a differential equation to determine how long it will take for the room to reach a safe to breathe level of 110 picocuries per cubic foot

The mass flow rate of the fluid remains constant in all steady flow process. a)- true b)- false

Asingle-geared blanking press has a stroke of 200 mm and a rated capacity of 320 kn. a cam driven ram is assumed to be capable of delivering the full press load at constant force during the last 15 percent of a constant-velocity stroke. the camshaft has an average speed of 90 rev/min and is geared to the flywheel shaft at a 6: 1 ratio. the total work done is to include an allowance of 16 percent for friction a) estimate the maximum energy fluctuation b) find the rim weight for an effective diameter of 1.2 m and a coefficient of speed fluctuation of 0.10

Slip occurs via two partial dislocations because of (a) the shorter path of the partial dislocation lines; (b) the lower energy state through partial dislocations; (c) the charge balance.