Electricity costs 12 cents per kilowatt hour. What does it cost to run a 60-W incandescent bulb for 1000 hours?

1. Energy used is E = P t = (60 W)(1000 h) = 60000 W h. 2. Converting to the billing unit gives E = 60.0 kW h. 3. Cost is energy times price: (60.0 kW h)(0.12 dollars per kW h). 4. That comes to 7.20 dollars of electricity for the 1000 hours. 5. 0.72 dollars is the slip of leaving the energy in watt hours when applying a per kilowatt hour price. _Source: OpenStax College Physics (CC BY 4.0), Ch 20 "Electric Current, Resistance, and Ohm's Law", section The Cost of Electricity_