Given data: m1 = -250 g t1 = -80°C m2 = -165 g t2 = -(-5)°C = 5°C t3 = -15°C св = -4200 Дж/(кг·°С) сл = 2100 Дж/(кг·°С)
a) To calculate the heat Q1, we can use the formula: Q1 = m1 * св * (t2 - t1) = -250 g * -4200 Дж/(кг·°С) * (5°C - (-80°C)) = -250 * -4200 * (5+80) = 250 * 4200 * 85 = 892500000 Дж
b) To calculate the heat Q2, we can use the formula: Q2 = m2 * сл * (t3 - t2) = -165 g * 2100 Дж/(кг·°С) * (-15°C - 5°C) = -165 * 2100 * (-15 - 5) = -165 * 2100 * -20 = 693000000 Дж
c) To calculate the heat Q3, we need to know the heat of fusion for ice. Unfortunately, that value is not given in the provided data. Please provide the specific heat of fusion for ice in order to proceed with the calculation.
d) To calculate the heat Q4, we can use the formula: Q4 = m2 * св * (t3 - 0) = -165 g * -4200 Дж/(кг·°С) * (-15°C - 0°C) = -165 * -4200 * -15 = 103950000 Дж
Finally, to calculate the total heat Q1, we can use the equation: Q1 = Q2 + Q3 + Q4 892500000 Дж = 693000000 Дж + Q3 +103950000 Дж
Solving for Q3: Q3 = 892500000 Дж - 693000000 Дж - 103950000 Дж Q3 = 952550000 Дж
Converting the calculated heat values to kJ/kg: Q1 = 892500000 Дж = 892.5 kJ/kg Q2 = 693000000 Дж = 693 kJ/kg Q3 = 952550000 Дж = 952.55 kJ/kg Q4 = 103950000 Дж = 103.95 kJ/kg
Comparing the calculated value of Q3 with the tabular value: Tabular value (λ) = 335 kJ/kg
The calculated value of Q3 (952.55 kJ/kg) is greater than the tabular value (335 kJ/kg).
