Cast iron and aluminum ingots of the same mass were heated to the melting point. which of these

Cast iron and aluminum ingots of the same mass were heated to the melting point. which of these bodies will require more energy to melt? how many times?

Given:

m1 = m2 = m – ingots of cast iron and aluminum of the same mass;

q1 = 100 kJ / kg = 10 ^ 5 J / kg – specific heat of melting of cast iron;

q2 = 390 kJ / kg = 3.9 * 10 ^ 5 J / kg is the specific heat of fusion of aluminum.

It is required to determine the ratio of the amount of energy required for complete melting of the Q2 / Q1 blanks.

Since, according to the condition of the problem, the bodies are already heated to the melting temperature, then:

Q2 / Q1 = q2 * m2 / (q1 * m1) = q2 * m / (q1 * m) = q2 / q1 = 3.9 * 10 ^ 5/10 ^ 5 = 3.9 times.

Answer: It takes 3.9 times more energy to melt aluminum.