Q:

(Power and Energy) If electricity costs $0.09 per kilowatt hour, find the cost (in dollars) of running each of the following electrical devices six hours per day for 30 days: a. A 60 watt incandescent light bulb b. An LED light bulb that emits the same light intensity as a 60 W incandescent light bulb, but uses 80 mA from a 120 V residential power wall outlet c. A 1500 W electric space heater that runs continuously over the six-hour daily period

Accepted Solution

A:
Answer:a) $0.97b) $0.16c) $24.30Step-by-step explanation:$0.09 per kilowatt hour = $0.09/kWh6h/day 30 days = 180ha) 60W*180h = 10800 Wh = 10.8kWh10.8kWh * $0.09/kWh = $0.97b) P = V*IV = 120VI = 80mA = 80/1000 = 0.08AP = 120*0.08 = 9.6W9.6W*180h = 1728 Wh = 1.728kWh1.728kWh * $0.09/kWh = $0.16c) 1500W*180h = 270000 Wh = 270kWh270kWh * $0.09/kWh = $24.30