iran-konkur 2014 Q170

iran-konkur · Other · konkur-riazi_1393 Not Maths
170. The coefficient of performance of a refrigerator is 4. This refrigerator converts 2 kilograms of water at $10°C$ into ice at $-8°C$. How many kilojoules of heat does the refrigerator release to the environment in this process?
\[ \left(L_f = 336\ \frac{\text{kJ}}{\text{kg}},\quad C_{\text{water}} = 4200\ \frac{\text{J}}{\text{kg.°C}},\quad C_{\text{ice}} = 2C_{\text{ice}}\right) \]
\[ (1)\ 433 \qquad (2)\ 493 \qquad (3)\ 867 \qquad (4)\ 987 \]
\textbf{170.} The coefficient of performance of a refrigerator is 4. This refrigerator converts 2 kilograms of water at $10°C$ into ice at $-8°C$. How many kilojoules of heat does the refrigerator release to the environment in this process?

\[
\left(L_f = 336\ \frac{\text{kJ}}{\text{kg}},\quad C_{\text{water}} = 4200\ \frac{\text{J}}{\text{kg.°C}},\quad C_{\text{ice}} = 2C_{\text{ice}}\right)
\]

\[
(1)\ 433 \qquad (2)\ 493 \qquad (3)\ 867 \qquad (4)\ 987
\]