Question

A 15-W compact fluorescent bulb produces the same amount of light as a 60-W incandescent bulb because the fluorescent bulb is more efficient at converting electrical energy to light energy. The purchase price of a compact fluorescent bulb is much more than that of an incandescent bulb, but the fluorescent bulb costs less over its lifetime because of its greater efficiency and because it lasts ten times longer than an incandescent bulb. Using the information below, determine how much time is needed before the extra purchase cost of the fluorescent bulb is "on" for five hours per day, and that the cost of electrical energy is 10c per kWh. Price of 60-W incandescent bulb: $0.05 Price of 15-W compact fluorescent bulb: $10.00 Lifetime of 60-W incandescent bulb: 1000h Lifetime of 15-W compact fluorescent bulb: 10000h (Ans= 13 months)

          A 15-W compact fluorescent bulb produces the same amount of light as a 60-W incandescent bulb because the fluorescent bulb is more efficient at converting electrical energy to light energy. The purchase price of a compact fluorescent bulb is much more than that of an incandescent bulb, but the fluorescent bulb costs less over its lifetime because of its greater efficiency and because it lasts ten times longer than an incandescent bulb. Using the information below, determine how much time is needed before the extra purchase cost of the fluorescent bulb is "on" for five hours per day, and that the cost of electrical energy is 10c per kWh.
Price of 60-W incandescent bulb: $0.05
Price of 15-W compact fluorescent bulb: $10.00
Lifetime of 60-W incandescent bulb: 1000h
Lifetime of 15-W compact fluorescent bulb: 10000h
(Ans= 13 months)

Show more…

Added by Eugenia W.

University Physics with Modern Physics

Hugh D. Young 14th Edition

Instant Answer

Solved by Expert Adam Moon

05/02/2022

Step 1

For the 60-W incandescent bulb: \[ \text{Daily energy consumption} = 60 \text{ W} \times 5 \text{ hours} = 300 \text{ Wh} = 0.3 \text{ kWh} \] For the 15-W compact fluorescent bulb: \[ \text{Daily energy consumption} = 15 \text{ W} \times 5 \text{ hours} = 75 Show more…

Show all steps

lock

Thanks for your feedback!

A 15-W compact fluorescent bulb produces the same amount of light as a 60-W incandescent bulb because the fluorescent bulb is more efficient at converting electrical energy to light energy. The purchase price of a compact fluorescent bulb is much more than that of an incandescent bulb, but the fluorescent bulb costs less over its lifetime because of its greater efficiency and because it lasts ten times longer than an incandescent bulb. Using the information below, determine how much time is needed before the extra purchase cost of the fluorescent bulb is "on" for five hours per day, and that the cost of electrical energy is 10c per kWh. Price of 60-W incandescent bulb: $0.05 Price of 15-W compact fluorescent bulb: $10.00 Lifetime of 60-W incandescent bulb: 1000h Lifetime of 15-W compact fluorescent bulb: 10000h (Ans= 13 months)

Play audio

Feedback

Powered by NumerAI

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Recommended Videos

Recommended Textbooks

Transcript

00:02 So it looks like your word problem is all about how power is related to what the electrical company charges per kilowatt hour.

00:12 So this is a fundamental problem dealing with the amount of time necessary and how much electrical energy is being utilized per hour.

00:26 So we know that from the word problem that the cost per kilowatt hour or 1 ,000 watts per hour is 10 cents.

00:36 We also know that the initial costs of a 15 watt bulb is $10, but it lasts 10 ,000 hours.

00:43 So it lasts a lot longer than a 60 watt bulb.

00:49 And the 60 watt bulb is 5 cents for 1 ,000 hours.

00:53 So it's going to take 10 bulbs of 60 watt bulbs.

00:58 To get 10 ,000 hours worth of output.

01:05 And then each bulb is gonna run for five hours per day.

01:09 So i went with the idea, well, what if i ran each of these bulbs for 10 ,000 hours, what would it cost overall? so in that time period of 10 ,000 hours, i can say that one 15 watt light bulb is used.

01:28 And so i get this equation, 0 .0015, that's how many kilowatts are being utilized, times some number of hours, which i called age, plus $10, that equals the cost.

01:45 So there's one of my equations.

01:48 And if i, i'm going to treat the $10 as my y intercept and the slope of the line is going to be 0 .0015.

01:55 So i kind of have a y equals mx plus b relationship going on here, this linear relationship.

02:04 The second equation is dealing with the, i'm going to need 10 light bulbs to last 10 ,000 hours for the 60 watt bulbs...

Ace is your personal tutor. It breaks down any question with clear steps so you can learn.

Start Using Ace

Continue solving this problem

Create a free account to:

View full step-by-step solution
Ask follow-up questions with Ace AI
Save progress and study later