Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 19: Q. 34 (page 544)

|| A 10 m×14 m house is built on a 12-cm-thick concrete slab.

What is the heat-loss rate through the slab if the ground temperature

is 5°C while the interior of the house is 22°C?

Short Answer

Expert verified

The power needed is 15.9 kW

Step by step solution

01

Formula to use in this problem

For thermal conduction,

dQdt=kAL∆T,

where dQ is the heat transferred in dt and dt is the time differential. If the time difference is unit,P=dQdt

02

Rearrangement of the equation and finding of the power needed

As our surface is rectangular, A=ab, where a and b are the dimensions of the floor. So,

P=kab∆TL=0.8·10·14·(22-5)0.12=1.59·104=15.9kW

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A satellite to reflect radar is a 2.0-m-diameter, 2.0-mm-thick spherical copper shell. While orbiting the earth, the satellite absorbs sunlight and is warmed to 50°C. When it passes into the earth's shadow, the satellite radiates energy to deep space. The temperature of deep space is actually 3K, as a result of the Big Bang 14 billion years ago, but it is so much colder than the satellite that you can assume a deep-space temperature of 0K. If the satellite's emissivity is 0.75, to what temperature, in C∘, will it drop during the 45 minutes it takes to move through the earth's shadow?

A 10cmdiameter cylinder contains argon gas at 10atmpressure and a temperature of50°C. A piston can slide in and out of the cylinder. The cylinder's initial length is 20cm.2500J of heat are transferred to the gas, causing the gas to expand at constant pressure. What are (a) the final temperature and (b) the final length of the cylinder?

You need to raise the temperature of a gas by 10°C. To use the least amount of heat energy, should you heat the gas at constant pressure or at constant volume? Explain.

Draw a first-law bar chart (see Figure 19.12) for the gas process in Figure EX19.9

FIGURE P19.62 shows a thermodynamic process followed by 120mgof helium.

a. Determine the pressure (in atm), temperature (in C∘), and volume in (cm3)of the gas at points 1,2 , and 3 . Put your results in a table for easy reading.

b. How much work is done on the gas during each of the three segments?

c. How much heat energy is transferred to or from the gas during each of the three segments?
See all solutions

Recommended explanations on Physics Textbooks

Thermodynamics

Read Explanation

Conservation of Energy and Momentum

Read Explanation

Fields in Physics

Read Explanation

Work Energy and Power

Read Explanation

Energy Physics

Read Explanation

Electricity

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free