How much energy does a piece of lead weighing 0.5 kg, taken at a temperature of 270C, acquire during melting?

univerkov | July 9, 2021 | education

Initial data: m (mass of a piece of lead) = 0.5 kg; t0 (initial lead temperature) = 270 ºС.

Reference values: tmelt (melting point) = 327 ºС; C (specific heat) = 140 J / (kg * K); λ (specific heat of fusion) = 25 * 10 ^ 3 J / kg.

Q = Q1 (heating lead to 327 ºС) + Q2 (melting lead) = C * m * (tmelt – t0) + λ * m.

Let’s make a calculation:

Q = 140 * 0.5 * (327 – 270) + 25 * 10 ^ 3 * 0.5 = 16 490 J.

Answer: When melted, a piece of lead will acquire 16,490 Joules of energy.

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.