Q: The local atmospheric pressure in Denver, Colorado (elevation 1610 m
The local atmospheric pressure in Denver, Colorado (elevation 1610 m), is 83.4 kPa. Air at this pressure and 20°C flows with a velocity of 8 m/s over a 1.5-m × 6-m flat plate w...
See AnswerQ: A semi-infinite aluminum cylinder (k = 237 W/
A semi-infinite aluminum cylinder (k = 237 W/m⋅K, α = 9.71 × 10−5 m2/s) of diameter D = 15 cm is initially at a uniform temperature of Ti = 115°C. The cylinder is now placed in water at 10°C, where h...
See AnswerQ: A 20-mm × 20-mm silicon chip is mounted
A 20-mm × 20-mm silicon chip is mounted such that the edges are flush in a substrate. The substrate provides an unheated starting length of 20 mm that acts as a turbulator. A turbulator is a device th...
See AnswerQ: Large steel plates 1.0 cm in thickness are quenched from
Large steel plates 1.0 cm in thickness are quenched from 600°C to 100°C by submerging them in an oil reservoir held at 30°C. The average heat transfer coefficient for both faces of steel plates is 400...
See AnswerQ: An airstream at 1 atm flows, with a velocity of 15
An airstream at 1 atm flows, with a velocity of 15 m/s, in parallel over a 3-m-long flat plate where there is an unheated starting length of 1 m. The airstream has a temperature of 20°C, and the heate...
See AnswerQ: A long roll of 2-m-wide and 0.
A long roll of 2-m-wide and 0.5-cm-thick 1-Mn manganese steel plate coming off a furnace at 820°C is to be quenched in an oil bath (cp = 2.0kJ/kg⋅K) at 45°C. Th...
See AnswerQ: In the effort to increase the removal of heat from a hot
In the effort to increase the removal of heat from a hot surface at 120°C, a cylindrical pin fin (kf = 237 W/m⋅K) with a diameter of 5 mm is attached to the hot surface. A...
See AnswerQ: Aluminum wires 4 mm in diameter are produced by extrusion. The
Aluminum wires 4 mm in diameter are produced by extrusion. The wires leave the extruder at an average temperature of 350°C and at a linear rate of 10 m/min. Before leaving the extrusion room, the wire...
See AnswerQ: Consider a person who is trying to keep cool on a hot
Consider a person who is trying to keep cool on a hot summer day by turning a fan on and exposing his body to airflow. The air temperature is 32°C, and the fan is blowing air at a velocity of 5 m/s. T...
See AnswerQ: During a picnic on a hot summer day, the only available
During a picnic on a hot summer day, the only available drinks were those at the ambient temperature of 90°F. In an effort to cool a 12-fluid-oz drink in a can, which is 5 in high and has a diameter o...
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