If 2 x 10^16 cm-3 boron atoms are added to silicon as a substitutional impurity and are distributed uniformly throughout the semiconductor, determine the distance between boron atoms in terms of the silicon lattice constant. (assume the boron atoms are distributed in a rectangular or cubic array.)

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false

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?

Air flows over a flat plate at a velocity of 3 m/sec and ambient conditions are, the pressure is 761 mm of hg and tempera- ture is 15°c. the plate is maintained at 85°c. if the length of the plate is 100 cm along the flow of the air, find out the heat lost by 50 cm of the plate which is measured from the trailing edge. plate width is 50 cm.