If a rubber band is stretched adiabatically, its temperature increases. (a) If the rubber band is stretched isothermally, does its entropy in- (b) If the rubber band is stretched adiabatically, does the internal crease, decrease, or stay the same? Energy increase, decrease, or stay the same?

Apreheater involves the use of condensing steam at 100°c on the inside of a bank of tubes to heat air that enters at 1 atm and 25°c. the air moves at 5 m/s in cross flow over the tubes. each tube is 1 m long and has an outside diameter of 10 mm. what is the minimum value of nl needed to achieve an outlet temperature of t 75 c? what is the corresponding pressure drop across the tube bank?