An older home is built in an area with a high radon flux (9.5 pCi m-2 s-1). The basement slab does not have a plastic vapor barrier so 90% of the radon flux passes into home. The house floor area is 2500 ft2 (232 m2), house volume is 20,000 ft3 (566 m3) and the air exchange rate is 1.5 ach. Neglect decay and ambient radon. Find the indoor steady-state radon concentration.

Draw the engineering stress-strain curve for (a) bcc; (b) fcc metals and mark important points.

Afan that can provide air speeds up to 60 m/s is to be used in a low-speed wind tunnel with atmospheric air at 35 c. if one wishes to use the wind tunnel to study flat-plate boundary layer behavior up to reynolds numbes of re 10, what is the minimum plate length that should be used? at what distance from the leading edge would transition occur if the critical reynolds nurnber were rer,e = 5 × 105?

An electric motor is used to drive a power press which makes steel turning moment diagrams 323 pressings from a metal sheet. the motor runs at a mean speed of 50 rev/s. the torque required is 10.0nm for 0.2s, followed by 1.0nm for0.3 s with this sequence then being repeated. what is the minimum power required of the motor and the moment of incrtia required for the t1ywhcel if the speed fluctuations are to be restricted to 1.5%?