Boiling water with a mass of m2 = 800 g is poured into water with a mass of m1 = 1 kg, the temperature of which

Boiling water with a mass of m2 = 800 g is poured into water with a mass of m1 = 1 kg, the temperature of which is t1 = 10 degrees. What is the final temperature t of the water?

Initial data: m1 (mass of cold water) = 1 kg; t1 (cold water temperature) = 10 ºС; m2 (mass of boiling water) = 800 g = 0.8 kg.

Constants: t2 (boiling water temperature) = 100 ºС.

The final water temperature after heat exchange is determined from the equality:

C * m1 * (t – t1) = C * m2 * (t2 – t).

m1 * (t – t1) = m2 * (t2 – t)

Substitute the known values:

1 * (t – 10) = 0.8 * (100 – t).

t – 10 = 80 – 0.8t.

1.8t = 90.

t = 90 / 1.8 = 50 ºС.

Answer: After heat exchange, the water temperature will be set to 50 ºС.