3. 4500J of heat was absorbed from a Carnot engine from a reservoir at 650K. The engine did some work, and discards some heat to a sink at 350K. Evaluate: (1) The heat that is discarded (ii) The work the engine did (iii) The efficiency of the system 4. A box with total wall area of 0.6m² and wall thickness 3cm is used to cool drinks. The inner and outer surface of the box are 0°C and 50°C respectively. Determine: (i) The rate of heat flow into the box (ii) The total heat flow in one day (ii) The mass of ice melted Take: Thermal conductivity of the box material to be 0.010 W / (m. K) Heat of fusion of ice to be L, = 3.34 × 105 J/kg 86,400 seconds are in a day.

3. 4500J of heat was absorbed from a Carnot engine from a reservoir at 650K. The engine did some work, and discards some heat to a sink at 350K. Evaluate: (1) The heat that is discarded (ii) The work the engine did (iii) The efficiency of the system 4. A box with total wall area of 0.6m² and wall thickness 3cm is used to cool drinks. The inner and outer surface of the box are 0°C and 50°C respectively. Determine: (i) The rate of heat flow into the box (ii) The total heat flow in one day (ii) The mass of ice melted Take: Thermal conductivity of the box material to be 0.010 W / (m. K) Heat of fusion of ice to be L, = 3.34 × 105 J/kg 86,400 seconds are in a day.