In a steel pan with a mass of 500 g, there was water with a mass of 1 kg at a temperature of 20 ° C.

In a steel pan with a mass of 500 g, there was water with a mass of 1 kg at a temperature of 20 ° C. The pan was put on fire and the water was heated to 100 • s. Determine the amount of heat transferred to the pot of water. (specific heat capacity of water is 4200J / kg • s, steel is 500J / kg • s)

Let there be given a steel pan with a mass of m г = 500 g = 0.5 kg. It contains water with a mass of m₂ = 1 kg at a temperature of t₁ = 20 ° C. A pot of water was put on fire, and the water was heated to t₂ = 100 ° C. At the same time, their temperature increased by:

Δt = t₂ – t₁ = 100 ° C – 20 ° C = 80 ° C.

To determine how much heat Q is transferred to a pot of water, it is necessary to find the sum of Q₁ and Q₂, where:

Q₁ = m₁ ∙ c₁ ∙ Δt is the amount of heat received by the steel pan, and

Q₂ = m₂ ∙ c₂ ∙ Δt – the amount of heat transferred to water.

In the reference tables we find that the specific heat capacity of water c₂ = 4200 J / (kg ∙ ° C), the specific heat capacity of steel c₁ = 500 J / (kg ∙ ° C). Then:

Q = Q₁ + Q₂;

Q = m₁ ∙ c₁ ∙ Δt + m₂ ∙ c₂ ∙ Δt;

Q = (m₁ ∙ c₁ + m₂ ∙ c₂) ∙ Δt.

Substitute the values ​​of physical quantities into the calculation formula and find the amount of heat transferred to the pan with water:

Q = (0.5 kg ∙ 500 J / (kg ∙ ° С) + 1 kg ∙ 4200 J / (kg ∙ ° С)) ∙ 80 ° С;

Q = 356000 J.

Answer: 356 MJ transferred to a pot of water.