Question

A particular household uses a 1.8 kW heater 2.2 h/day ("on" time), four 105 W lightbulbs 5.0 h/day , a 2.5 kW electric stove element for a total of 1.0 h/day, and miscellaneous power amounting to 1.5 kWh/day .If electricity costs $0.105 per kWh, what will be their monthly bill (30 d)? How much coal (which produces 7500 kcal/kg) must be burned by a 35 % -efficient power plant to provide the yearly needs of this household?

Answer 1