Task data: m (mass of water to be heated) = 45 kg; t0 (initial temperature) = 12 ºС; t (final heating temperature) = 61 ºС.
Reference values: Sv (specific heat of water) = 4200 J / (kg / K).
The required amount of heat for heating 45 kg of water is determined by the formula: Q = Sv * m * (t – t0).
Calculation: Q = 4200 * 45 * (61 – 12) = 9 261 000 J ≈ 9.26 MJ.
Answer: 9.26 MJ of heat must be spent on heating water.
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