Calculate the amount of heat required to heat and melt 40 kg copper, the initial temperature of which is 250C.

univerkov | July 5, 2021 | education

These tasks: m (mass of copper for heating and melting) = 40 kg; t0 (initial copper temperature) = 250 ºС.

Reference values: Cm (specific heat of copper) = 400 J / (kg * K); tmelt (melting point) = 1084.5 ºС; λ (specific heat of fusion) = 2.1 * 105 J / kg.

The required heat for melting 40 kg of copper: Q = Q1 + Q2 = Cm * m * (tmelt – t0) + λ * m.

Calculation: Q = 400 * 40 * (1084.5 – 250) + 2.1 * 105 * 40 = 21,752,000 J (≈ 21.8 MJ).

Answer: Melting 40 kg of copper requires 21.8 MJ of heat.

One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.