How much energy is needed to turn 400 g of copper into a liquid state taken at a temperature of 83 degrees?

1) Before melting copper, it must be heated to the melting temperature t = 1085 degrees, which we take from the reference tables. To calculate how much heat copper must receive in order to heat up to this temperature, we use the formula: Q = m • c • Δt. Specific heat capacity of copper c = 400 J / (kg • deg), temperature change Δt = 1085 – 83; Δt = 1002 degrees, copper mass m = 400 g = 0.4 kg. We substitute the values ​​of physical quantities: Q = 0.4 kg • 400 J / (kg • deg) • 1002 deg = 160 320 J
2) To calculate how much heat copper must receive in order to go into a liquid state, we use the formula Q = λ • m, where the specific heat of fusion of copper λ = 0.21 MJ / kg. We substitute the values ​​of physical quantities: Q = 0.4 kg • 210,000 J / kg = 84,000 J.
3) Let’s find how much energy is required for both processes. Q = 160320 J + 84000 J = 244320 J.
Answer: 244320 J of energy is needed to transfer this copper into a liquid state.