Consider a 1000-W iron whose base plate is made of 0.5-cm-thick aluminum alloy (p= 2770 kg/m3 and cp = 875 J/kg · °C). The base plate has a surface area of 0.03 m2. Initially, the iron is in thermal equilibrium with the ambient air at 22°C. Assuming 85 percent of the heat generated in the resistance wires is transferred to the plate; determine the minimum time needed for the plate temperature to reach 140°C.

Consider a 1000-W iron whose base plate is made of 0.5-cm-thick aluminum alloy (p= 2770 kg/m3 and cp = 875 J/kg · °C). The base plate has a surface area of 0.03 m2. Initially, the iron is in thermal equilibrium with the ambient air at 22°C. Assuming 85 percent of the heat generated in the resistance wires is transferred to the plate; determine the minimum time needed for the plate temperature to reach 140°C.

Electricity for Refrigeration, Heating, and Air Conditioning (MindTap Course List)

10th Edition

ISBN:9781337399128

Author:Russell E. Smith

Publisher:Russell E. Smith

Chapter12: Electronic Control Devices

Section: Chapter Questions

Problem 14RQ

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