A furnace uses preheated air to improve its fuel efficiency. Determine the adiabatic flame temperature when the furnance is operating at a mass air-fuel ratio of 16 for air preheated to 600 K. The fuel enters at 300 K. Assume the following simplified thermodynamic properties: Tref = 300 K MWFUEL=MWAIR=MWPROD = 29 kg/kmol cp, fuel =cp, air= cp, prod = 1200 J / kg-K
hf, air = hf, prod = 0 hf, fuel = 4x107 J/kg

If a particle moves along a path such that r : (3 sin t) m and ? : 2t rad, where t is in seconds. what is the particle's acceleration in m/s in 4 seconds? a)- 16.43 b)- 16.29 c)- 15.21 d)- 13.79

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Which of the following controllers anticipates the future from the slope of errors over time? a)-proportional b)-on/off c)-integral d)-derivative.