Pieces of ice are thrown into a saucepan with boiling water weighing 1 kg at 0 ° C. How much ice needs to be thrown so that the water temperature is 40 ° C. Heat capacity of the pan 1000 J / ° С
Let us turn to the formula for the internal energy of a body: Q = m * C * T, where m is the mass, C is the specific heat, T is the temperature. Then, using the law of conservation of energy, the energy balance of the system will look like this:
m1 * C1 * (T1 – T) + m2 * C2 * (T1 – T) = m3 * C1 * (T – T2), where m1 m2 m3 are the masses of water, saucepan and ice. T1 = 100, T2 = 0, T = 40.
m1 * C1 * 60 + m2 * C2 * 60 = m3 * C1 * 40;
m3 = 3/2 * (m1 * C1 + m2 * C2) / C1;
m3 = 3/2 * (m1 + m2 * C2 / C1).
The problem does not specify the mass of the pan m2.
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