Consider a fuel cell operating at 800∘C, 1 atm. In the cathode, humidified air is supplied with the mole fraction of water vapor equal to 0.1. If the fuel cell employs circular flow channels with a diameter of 1 mm, find the maximum velocity of air that can be used while still maintaining laminar flow. Compare your result to Example 5.2.

Ajet plane has a sound level of 120 db at a distance of 60 m. what is the q23. sound level at a distance of 6.0 km? (60)2 (6000)? om solution 80db db, hint: 16x assume ultrasound waves travel through the body of an animal at 1540 q24. m/s. if a 30,000 hz signal were reflected off a portion of a heart which was moving toward the source at 3 m/s, what frequency signal would return to the stationary source? solution 30.117hz

Which notation is used to represent an alpha particle? a. b. c. d.

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final