Initial data: m (bar weight) = 0.5 kg; tн (initial temperature of the bar) = 20 ºС.
Reference data: tpl. (zinc melting point) = 419.6 ºС; C (specific heat of zinc) = 400 J / (kg * K); λ (specific heat of fusion of zinc) = 112.2 * 10 ^ 3 J / kg.
The energy that the bar will acquire: Q = Q1 + Q2 = C * m * (tpl – tn) + λ * m.
Let’s perform the calculation: Q = 400 * 0.5 * (419.6 – 20) + 112.2 * 10 ^ 3 * 0.5 = 136,020 J.
Answer: A zinc bar when melted will acquire 136,020 Joules of thermal energy.
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