Q: A 40-W power transistor is to be cooled by attaching
A 40-W power transistor is to be cooled by attaching it to one of the commercially available heat sinks shown in Table 17–6. Select a heat sink that will allow the case temperature o...
See AnswerQ: Consider two identical people each generating 60 W of metabolic heat steadily
Consider two identical people each generating 60 W of metabolic heat steadily while doing sedentary work and dissipating it by convection and perspiration. The first person is wearing clothes made of...
See AnswerQ: Cold conditioned air at 12°C is flowing inside a 1
Cold conditioned air at 12°C is flowing inside a 1.5-cm-thick square aluminum (k = 237 W/m⋅K) duct of inner cross section 22 cm × 22 cm at a mass flow rate of 0.8 kg/s. The duct is exposed to air at 3...
See AnswerQ: Hot water is flowing at an average velocity of 1.5
Hot water is flowing at an average velocity of 1.5 m/s through a cast iron pipe (k = 52 W/m⋅K) whose inner and outer diameters are 3 cm and 3.5 cm, respectively. The pipe passes through a 15 m-long se...
See AnswerQ: The plumbing system of a house involves a 0.5-
The plumbing system of a house involves a 0.5-m section of a plastic pipe (k = 0.16 W/mâ‹…K) of inner diameter 2 cm and outer diameter 2.4 cm exposed to the ambient air. During a cold...
See AnswerQ: Steam at 260°C is flowing inside a steel pipe (
Steam at 260°C is flowing inside a steel pipe (k = 61 W/m⋅K) whose inner and outer diameters are 10 cm and 12 cm, respectively, in an environment at 20°C. The heat transfer coefficients inside and out...
See AnswerQ: An exercise room has six weight-lifting machines that have no
An exercise room has six weight-lifting machines that have no motors and seven treadmills each equipped with a 2.5-hp (shaft output) motor. The motors operate at an average load factor of 0.7, at whic...
See AnswerQ: A spherical vessel, 3.0 m in diameter (and
A spherical vessel, 3.0 m in diameter (and negligible wall thickness), is used for storing a fluid at a temperature of 0°C. The vessel is covered with a 5.0-cm-thick layer of an insulation (k = 0.20 W...
See AnswerQ: Consider a window glass consisting of two 4-mm thick glass
Consider a window glass consisting of two 4-mm thick glass sheets pressed tightly against each other. Compare the heat transfer rate through this window with that of one consisting of a single 8-mm-th...
See AnswerQ: One wall of a refrigerated warehouse is 10.0 m high
One wall of a refrigerated warehouse is 10.0 m high and 5.0 m wide. The wall is made of three layers: 1.0-cm-thick aluminum (k = 200W/m⋅K), 8.0-cm thick fiberglass (k = 0.038W/m⋅K), and 3.0-cm-thick g...
See Answer
