Your home loses energy in the winter through doors, windows, and any poorly insulated walls. A sliding glass door (6 ft × 6.5 ft with 0.5 inch of insulating glass) allows 1.0 × 10⁶ J/h to pass through the glass if the inside temperature is 22°C (72°F) and the outside temperature is 0°C (32°F). What quantityof energy, expressed in kilojoules, is lost per day? Assume that your house is heated by electricity. How many kilowatt-hours of energy are lost per day through the door? (See Study Question 24 for the definition of a kilowatt-hour.)

Data given in Question 24

Calculate the energy used, in kilojoules, to power a 100‑watt lightbulb continuously over a 24-hour period. How much coal would have to be burned to provide this quantity of energy, assuming that the enthalpy of combustion of coal is 33 kJ/g and the power plant has an efficiency of 35%? [Electrical energy for home use is measured in kilowatt hours (kW-h). One watt is defined as 1 J/s, and1 kW-h is the quantity of energy transferred when 1000 watt is dispensed over a 1.0-hour period.]