5-37 A 40-L electrical radiator containing heating oil is placed in a 50-m³ room. Both the room and the oil in the radi- ator are initially at 10°C. The radiator with a rating of 2.4 kW is now turned on. At the same time, heat is lost from the room at an average rate of 0.35 kJ/s. After some time, the average temperature is measured to be 20°C for the air in the room, and 50°C for the oil in the radiator. Taking the density and the specific heat of the oil to be 950 kg/m³ and 2.2 kJ/kg.°C, respectively, determine how long the heater is kept on. Assume the room is well-sealed so that there are no air leaks. Room 10°C Q Radiator FIGURE P5-37