   Chapter 11, Problem 51P

Chapter
Section
Textbook Problem

A rectangular glass window pane on a house has a width of 1.0 m, a height of 2.0 m, and a thickness of 0.40 cm. Find the energy transferred through the window by conduction in 12 hours on a day when the inside temperature of the house is 22°C and the outside temperature is 2.0°C. Take surface air layers into consideration.

To determine
The energy transferred through the window by conduction.

Explanation

Given info: Thickness of the glass plane is 0.40 cm thick, width of the glass window pane is 1.0 m, height is 2.0 m. duration of conduction is 12 hours, Inside temperature is 22°C and outside temperature is 2.0°C . Surface air layers are considered.

Formula to calculate R factor for glass pane is,

Rpane=(Lpanekpane)

• Rpane is the R factor for pane,
• Lpane is the thickness of the glass pane,
• kpane is the thermal conductivity of the glass pane,

Substitute 0.40 cm for Lpane and 0.8W/m°C for kpane to find Rpane .

Rpane=(0.40×102m0.8W/m°C)=5.0×103m2°CW

Air layer is present on the either side of the glass panes.

The R factor for the thermo pane is,

R=Rpane+2Rair (1)

Formula to calculate area of the rectangular surface is,

A=hw (2)

• A is the rectangular area through which is energy transferred,
• h is the height of the surface,
• w is the width of the surface,

Formula to determine the rate of energy transferred through 1.0m2 of the window is,

Q=A(ThTc)Rt (3)

• Q is the energy transfer,
• Th is the inside temperature,
• Tc is the outside temperature,
• t is the time duration of heat transfer,

Use equation (1) (2)to rewrite equation (3).

Q=(hw)(ThTc)Rpane+2Rairt

Substitute 1

Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started

The best way to control salt intake is to cut down on processed and fast foods. T F

Nutrition: Concepts and Controversies - Standalone book (MindTap Course List)

What factors resist the contraction of a cloud of interstellar matter?

Horizons: Exploring the Universe (MindTap Course List)

What are genomes?

Human Heredity: Principles and Issues (MindTap Course List)

What is a genetic mutation?

Chemistry for Today: General, Organic, and Biochemistry 