How much heat is required to melt 24.5 kg of aluminum taken at a temperature of 20 degrees?
| July 10, 2021 | education
Q = Q1 + Q2.
Q1 = C * m * (tк – tн), where C is the specific heat capacity of aluminum (C = 903 J / (K * kg)), m is the mass (m = 24.5 kg), tк is the melting point (tк = 660 ºС), tн – initial temperature (tн = 20 ºС).
Q1 = C * m * (tк – tн) = 920 * 24.5 (660 – 20) = 14425600 J.
Q2 = λ * m, where λ is the specific heat of fusion (λ = 3.9 * 10 ^ 5 J / kg).
Q2 = (3.9 * 10 ^ 5) * 24.5 = 9555000 J.
Q = Q1 + Q2 = 14425600 + 9555000 = 23980600 J ≈ 24 MJ.
Answer: You need to spend 24 MJ of energy.
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