Apreheater involves the use of condensing steam at 120°c on the inside of a bank of tubes to heat air that enters at 1 atm and 20°c. the air moves at 10 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 to = 80°c? what is the corresponding pressure drop across the tube bank? note: st = sl = 15 mm

Which feature of a heating curve indicates a change ofn state

Imagine you are riding on a yacht in the ocean and traveling at 20 mph. you then hit a golf ball at 100 mph from the deck of the yacht. you see the ball move away from you at 100mph, while a person standing on a near by beach would observe your golf ball traveling at 120 mph (20 mph + 100 mph). now imagine you are aboard the hermes spacecraft traveling at 0.1c (1/10 the speed of light) past mars and shine a laser from the front of the ship. you would see the light traveling at c (the speed of light) away from your ship. according to einstein’s special relativity, how fast will a person on mars observe the light to be traveling? a) 0.1c (1/10 the speed of light) b) c (the speed of light) c)1.1c (c+0.1c)

In positive numbers less than 1, the zeros between the decimal point and a non-zero number are blank significant