Q: A hydraulic turbine has 85 m of elevation difference available at a
A hydraulic turbine has 85 m of elevation difference available at a flow rate of 0.25 m3/s, and its overall turbine–generator efficiency is 91 percent. Determine the electric power output of this turb...
See AnswerQ: A body at an initial temperature of Ti is brought into a
A body at an initial temperature of Ti is brought into a medium at a constant temperature of T∞. How can you determine the maximum possible amount of heat transfer between the body and the surrounding...
See AnswerQ: Reconsider Prob. 17–73E. Using appropriate software, investigate
Reconsider Prob. 17–73E. Using appropriate software, investigate the effects of the thermal conductivity of the pipe material and the outer diameter of the pipe on the length of the...
See AnswerQ: For which solid is the lumped system analysis more likely to be
For which solid is the lumped system analysis more likely to be applicable: an actual apple or a golden apple of the same size? Why?
See AnswerQ: A 2.2-mm-diameter and 14-m
A 2.2-mm-diameter and 14-m-long electric wire is tightly wrapped with a 1-mm-thick plastic cover whose thermal conductivity is k = 0.15 W/mâ‹…K. Electrical measurements indicate that a...
See AnswerQ: In a meat processing plant, 2-cm-thick steaks
In a meat processing plant, 2-cm-thick steaks (k = 0.45 W/m⋅K and α = 0.91 × 10−7 m2/s) that are initially at 25°C are to be cooled by passing them through a refrigeration room at −11°C. The heat tran...
See AnswerQ: Consider a 1.5-m-high electric hot-
Consider a 1.5-m-high electric hot-water heater that has a diameter of 40 cm and maintains the hot water at 60°C. The tank is located in a small room whose average temperature is 27Â&...
See AnswerQ: A 10-cm-thick aluminum plate (α = 97
A 10-cm-thick aluminum plate (α = 97.1 × 10−6 m2/s) is being heated in liquid with temperature of 500°C. The aluminum plate has a uniform initial temperature of 25°C. If the surface temperature of t...
See AnswerQ: Chilled water enters a thin-shelled 4-cm-diameter
Chilled water enters a thin-shelled 4-cm-diameter, 200-m-long pipe at 7°C at a rate of 0.98 kg/s and leaves at 8°C. The pipe is exposed to ambient air at 30°C with a heat transfer coefficient of 9 W/m...
See AnswerQ: Layers of 23-cm-thick meat slabs (k =
Layers of 23-cm-thick meat slabs (k = 0.47 W/m⋅K and α = 0.13 × 10−6 m2/s) initially at a uniform temperature of 7°C are to be frozen by refrigerated air at −30°C flowing at a velocity of 1.4 m/s. The...
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