Atmospheric air is in parallel flow (u=10 m/s, to= 15°c) over a flat heater surface that is to be maintained at a temperature of 90°c. the heater surface area is 0.25 m^2, and the airflow is known to induce a drag forde of 0.15 n on the heater. what is the electrical power needed to maintain the prescribed surface temperature?

Different types of steels contain different elements that alter the characteristics of the steel. for each of the following elements, explain what the element does when alloyed with steel.

Determine whether or not it is possible to compress air adiabatically from k to 140 kpa and 400 k. what is the entropy change during this process?

Asteam is contained in a rigid tank with a volume of 1 m3. initially, the pressure and temperature are 7 bar and 500 oc, respectively. the temperature drops due to cooling process. determine: (1) the temperature at which condensation begins in °c, (2) the fraction of the total mass that has condensed when the pressure decreased to 0.5 bar. (3) the volume in m3 occupied by saturated liquid at the final state?