The base plate of an iron has a thickness of L = 7 mm and is made from an aluminum alloy (p = 2800 kg/m₃ ∙c = 900 J/kg ∙ K, k = 180 W/m ∙ K, ε = 0.80). An electric resistance heater is attached to the inner surface of the plate, while the outer surface is exposed to ambient air and large surroundings at T – x. = T_sur = 25°C. The areas of both the inner and outer surfaces are A_s = 0.040 m².

If an approximately uniform heat flux of q"_h = 1.25 x 10⁴ W/m² is applied to the inner surface of the base plate and the convection coefficient at the outer surface is h = 10W/m² ∙ K, estimate the time required for the plate to reach a temperature of 135°C.

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Surroundings, TSu sur Air Baseplate (p, c, k, ɛ, qi, 1, A,)