Calculate the amount of heat radiated per second by a body of surface

1.	Calculate the amount of heat radiated per second by a body of surface area 12cm2 kept in thermal equilibrium in a room at temperature 20°C. The emissivity of the surface = 0.80 and σ = 6.0 x 10-8 W/m2-K4.
Answer» A = 12cm² = 12 × 10^–4m² T = 20°C = 293K e = 0.8 σ = 6 × 10^–8w/m²-k⁴ Q/t = AeσT⁴= 12 × 10^–4 0.8 × 6 × 10^–8 (293)⁴ = 4.245 × 1012 × 10^–13 = 0.4245 ≈ 0.42

Calculate the amount of heat radiated per second by a body of surface area 12cm2 kept in thermal equilibrium in a room at temperature 20°C. The emissivity of the surface = 0.80 and σ = 6.0 x 10-8 W/m2-K4.

Answer»

A = 12cm² = 12 × 10^–4m² T = 20°C = 293K
e = 0.8 σ = 6 × 10^–8w/m²-k⁴

Q/t = AeσT⁴= 12 × 10^–4 0.8 × 6 × 10^–8 (293)⁴ = 4.245 × 1012 × 10^–13 = 0.4245 ≈ 0.42

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Calculate the amount of heat radiated per second by a body of surface area 12cm2 kept in thermal equilibrium in a room at temperature 20°C. The emissivity of the surface = 0.80 and σ = 6.0 x 10-8 W/m2-K4.

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