일반물리학 1 — Temperature, Heat, and the First Law of Thermodynamics: Problem 42

42 A 0.600 kg sample is placed in a cooling apparatus that removes energy as heat at a constant rate. Figure 18-38 gives the temperature T of the sample versus time t; the horizontal scale is set by $t_s = 80.0$ min. The sample freezes during the energy removal. The specific heat of the sample in its initial liquid phase is $3000 \text{ J/kg} \cdot \text{K}$. What are (a) the sample’s heat of fusion and (b) its specific heat in the frozen phase?