Question

your utility company charges 13 cents per kilowatt-hour of electricity. complete parts (a) and (b) below.
a. what is the daily cost of keeping lit a 100-watt light bulb for 13 hours each day?
b. how much will you save in a year if you replace the bulb with an led bulb that provides the same amount of light using only 20 watts of power?
a. the daily cost of keeping lit a 100-watt light bulb for 13 hours each day is $square$.
(round to three decimal places as needed.)

Explanation:

Step1: Calculate the energy consumption in kilowatt - hours for the 100 - watt bulb

The formula for energy consumption \(E\) (in kilowatt - hours) is \(E=\frac{P\times t}{1000}\), where \(P\) is power in watts and \(t\) is time in hours.
For \(P = 100\) watts and \(t=13\) hours, \(E=\frac{100\times13}{1000}=1.3\) kWh.

Step2: Calculate the daily cost

The cost per kilowatt - hour is \(13\) cents or \(\$0.13\).
The daily cost \(C\) is \(C = E\times\) cost per kWh.
Substituting \(E = 1.3\) kWh and cost per kWh=\(\$0.13\), we get \(C=1.3\times0.13=\$0.169\).

Answer:

\(0.169\)