The temperature in an electric oven is 165°C. The temperature at the outer surface in the kitchen is 55°C. The oven (surface area = 1.6 m2) is insulated with material that has a thickness of 0.023 m and a thermal conductivity of 0.045 J/(sm°C). a) How much energy is used to operate the oven for 7 hours? (b) At a price of $0.10 per kilowatt hour for electrical energy, what is the cost of operating the oven?