Combustion gases passing through a 3-cm-internal-diameter circular tube are used to vaporize waste water at atmospheric pressure. hot gases enter the tube at 115 kpa and 250°c at a mean velocity of 5 m/s, and leave at 150°c. if the average heat transfer coefficient is 120 w/m2k and the inner surface temperature of the tube is 110°c, determine (a) the tube length and (b) the rate of evaporation of water.

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

Two flowing streams of argon gas are adiabatically mixed to form a single flow/stream. one stream is 1.5 kg/s at 400 kpa and 200 c while the second stream is 2kg/s at 500 kpa and 100 ? . it is stated that the exit state of the mixed single flow of argon gas is 150 c and 300 kpa. assuming there is no work output or input during the mixing process, does this process violate either the first or the second law or both? explain and state all your assumptions.

Steel is coated with a thin layer of ceramic to protect against corrosion. what do you expect to happen to the coating when the temperature of the steel is increased significantly? explain.