P_{\sum} = A σ (T_{i}^{4} - T_{k}^{4}) = 2 \times 5, 67 \cdot 10^{- 8} (8, 77 \cdot 10^{9} - 7, 37 \cdot 10^{9}) \approx 160 W

${P_\sum=A \sigma (T_i^4-T_k^4 )=2 \times 5,67 \cdot{10}^{-8} (8,77 \cdot 10^9 - 7,37 \cdot 10^9 ) \approx 160\, \mathrm{W}}$

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