How many degrees will the temperature of water weighing 5 kg, taken at 20 C

How many degrees will the temperature of water weighing 5 kg, taken at 20 C, rise if an iron weight weighing 2 kg, heated to 100 C.

Given: m1 (mass of water) = 5 kg; t1 (water temperature before lowering the weight) = 20 ºС; m2 (weight of the weight) = 2 kg; t2 (weight heating temperature) = 100 ºС.

Reference values: C1 (specific heat capacity of water) = 4200 J / (kg * ºС); C2 (specific heat capacity of iron) = 460 J / (kg * ºС).

1) Increase in water temperature:

C1 * m1 * (tp – t1) = C2 * m2 * (t2 – tp).

4200 * 5 * (tr – 20) = 460 * 2 * (100 – tr).

21000tr – 420000 = 92000 – 920tr.

21920tr = 512000.

tр = 23.36 ºС.

2) Temperature change: Δt1 = 23.36 – 20 = 3.36 ºС.