A pitcher has wall area 3 × 1 0 − 2 m², wall thickness 2 mm and conductivity 0.9 W/m°C. The surroundings are at 40°C and 0.12 g of water evaporates per second from the outer surface in steady state. L

Question

A pitcher has wall area 3 × 1 0 − 2 m², wall thickness 2 mm and conductivity 0.9 W/m°C. The surroundings are at 40°C and 0.12 g of water evaporates per second from the outer surface in steady state. L = 2.27 × 1 0 6 J/kg. Find the water temperature, in °C.

TestHub · Accepted Answer

Evaporation takes 0.12 × 1 0 − 3 × 2.27 × 1 0 6 = 272.4 W by conduction. Δ T = k A P d ​ = 0.9 × 3 × 1 0 − 2 272.4 × 2 × 1 0 − 3 ​ = 20.2 . Water = 40 − 20.2 = 19.8 ∘ C.

Physics - Heat & Thermo Question with Solution | TestHub

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