What amount of heat will be released when a 166 g lead cylinder is cooled from 61 to 16 degrees?

Solution.
When a substance with mass m and heat capacity c is cooled, from temperature t₁ to temperature t₂, the amount of heat Q is released, determined using the formula: Q = m ∙ c ∙ (t₂ – t₁). It is known from the problem statement that a lead cylinder with a mass of m = 166 g = 0.166 kg was cooled from a temperature t₁ = 61 ° C to a temperature t₂ = 16 ° C. The heat capacity of lead is found in the reference tables with = 140 J / (kg ∙ deg). Let’s substitute the values ​​of physical quantities into the calculation formula and find how much heat will be released when the lead cylinder is cooled: Q = 0.166 ∙ 140 ∙ (16 ° – 61 °); Q = – 1045.8 J. The “─” sign indicates that the body is losing energy.
Answer: 1045.8 J will be released when the lead cylinder is cooled.