GE J-79 turbojet produces a thrust of 10,000lbs at sea level. The inlet diameter is 3.19 ft. If an airplane equipped with the J79 is flying at standard sea level with a velocity of 1,000 ft/sec, estimate the jet velocity relative to the airplane.

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?