- Air at 105 kPa and 37°C flows upward through a 6-cm-diameter inclined duct at a rate of Q (L/s). The density of air at this temperature and pressure is 1.10 Kg/m³. The duct diameter is then reduced to 4 cm through a reducer. The pressure change across the reducer is measured by a water manometer. The elevation difference between the two points on the pipe where the two arms of the manometer are attached is 0.20 m. Determine the differential height between the fluid levels of the two arms of the manometer. Air Q (L/s) 90

An iron bar 2.0 cm x 3.0 cm x 10.0 cm at a temperature of 95 °C is dropped into a barrel of water at 25 °C. The barrel is large enough so that the water temperature rises negligibly as the bar cools. The rate at which heat is transferred from the bar to the water is given by the expression Q (J/min) = UA (Th - Tw.) where U = 0.05 J/(min cm °C)] is a (cm) is the exposed surface area of the bar, T₁, and T are the surface temperature of the bar and the water temperature, respectively. The heat capacity of the bar is 0.46 J/(g °C). Heat conduction in iron is rapid enough for the temperature T, to be considered uniform throughout the bar. a) Write an energy balance on the bar M = (60 cm³)(7.7 g/cm³) = 462 g C₁ = 0.46 kJ/(kg-°C), T = 25°C U= 0.050 J/(min-cm² °C) |4=2[(2)(3) + (2)(10) +(3)(10)]cm² = 112 cm²

The compressed air requirements of a textile factory are met by a large compressor that draws in 0.6 m3/s air at atmospheric conditions of 20°C and 1 bar (100 kPa) and consumes 300 kW electric power when operating. Air is compressed to a gage pressure of 8 bar (absolute pressure of 900 kPa), and compressed air is transported to the production area through a 15-cm-internal-diameter, 83-m-long, plastic (smooth) pipes with a surface roughness of 0.15 mm. The average temperature of compressed air in the pipe is 60°C. The compressed air line has 8 elbows with a loss coefficient of 0.6 each. In order to reduce the head losses in the piping and thus the power wasted, someone suggests doubling the diameter of the 83-m-long compressed air pipes. Calculating the reduction in wasted power, and determine if this is a worthwhile idea. Considering the cost of replacement, does this proposal make sense to you?

Argon is accelerated in a nozzle from 32 m/s at 666 K to 441 m/s and 196 kPa. If the heat loss is equal to 5.1 kJ/kg, determine the gas temperature at outlet in K to 1 decimal place. Take the gas constant as 0.2 (kPa m3)/(kg K) and assume constant specific heats cp=0.5 kJ/(kg K) and cv=0.3 kJ/(kg K).