50 liters of hot water at a temperature of 55 * C and 25 liters of water at a temperature of 10 * C were poured into

50 liters of hot water at a temperature of 55 * C and 25 liters of water at a temperature of 10 * C were poured into the bath. stirring the water, the temperature of the mixture was measured. It turned out to be equal to 40 * С. Determine the amount of heat given off by hot water and received by cold water.

To find the heat given up by hot water (obtained by cold water) as a result of the past heat exchange, we apply the formula: Cw * mg * (tg – tp) = Q (heat) = Cw * mx * (tp – tx).

Constants and variables: Cv – beats. heat capacity of water (Sv = 4.2 * 10 ^ 3 J / (kg * ºС)); mg is the mass of hot water (mg = 50 kg (Vg = 50 l)); tg – initial temperature of hot water (tg = 55 ºС); tр – equilibrium temperature (tр = 40 ºС); mх is the mass of added cold water (mх = 25 kg (V = 25 l)); tх – initial temperature of cold water (tх = 10 ºС).

Calculation: 1) Q = Cw * mg * (tg – tr) = 4.2 * 10 ^ 3 * 50 * (55 – 40) = 3.15 * 10 ^ 6 J = 3.15 MJ.

2) Q = Cw * mx * (tr – tx) = 4.2 * 10 ^ 3 * 25 * (40 – 10) = 3.15 * 10 ^ 6 J = 3.15 MJ.

Answer: Hot water will transfer 3.15 MJ of heat to cold.