1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
lana66690 [7]
3 years ago
12

A carpenter builds an exterior house wall with a layer of wood 3.0 cm thick on the outside and a layer of Styrofoam insulation 2

.4 cm thick on the inside wall surface. The wood has k=0.080W/(m?K), and the Styrofoam has k= 0.010 W/(m?K). The interior surface temperature is 20.0 ?C , and the exterior surface temperature is -13.0 ?C
A.) What is the temperature at the plane where the wood meets the Styrofoam? _______ Celsius
B.) What is the rate of heat flow per square meter through this wall? ______W/m^2
Physics
1 answer:
Leno4ka [110]3 years ago
7 0

Answer:

A. T=15.54 °C

B. Q/A= 0.119 W/m2

Explanation:

To solve this problem we need to use the Fourier's law for thermal conduction:

Q= kA\frac{dT}{dx}

Here, the rate of flow per square meter must be the same through the complete wall. Therefore, we can use it to find the temperature at the plane where the wood meets the Styrofoam as follows:

\frac{Q}{A} =\frac{T_1-T_0}{d_w}k_w=\frac{T_2-T_1}{d_s}k_s\\T_1(\frac{k_w}{d_w}+\frac{k_s}{d_s})=T_2\frac{k_s}{d_s}+T_0\frac{k_w}{d_w}\\T_1=\frac{T_2\frac{k_s}{d_s}+T_0\frac{k_w}{d_w}}{\frac{k_w}{d_w}+\frac{k_s}{d_s}}\\T_1= 15.54 \°C

Then, to find the rate of heat flow per square meter, we have:

\frac{Q}{A}=\frac{T_1-T_0}{d_w}k_w=0.119 \frac{W}{m^2}\\\frac{Q}{A}=\frac{T_2-T_1}{d_s}k_s= 0.119 \frac{W}{m^2}

T_0: Temperature \ in \ the \ house\\T_1: Temperature \ at \ the \ plane \ between \ wood \ and \ styrofoam\\T_2: Temperature \ outside\\k_w: k \ for \ wood\\d_w: wood \ thickness\\k_s: k \ for \ styrofoam\\d_s: styrofoam \ thickness

You might be interested in
Friction can be reduced by using ___________.
allsm [11]

Answer:

Make the surfaces little more smoother. ...

Lubrication is another way to make a surface smoother. ...

Make the object more streamlined. ...

Reduce the Normal force acting between the surfaces in contact. ...

Reduce the contact between the surfaces, so that less number of bonds will be formed.

6 0
3 years ago
Read 2 more answers
Calculate the force of an object that has a mass of 10kg and an acceleration of 4m/s²
ICE Princess25 [194]
The answer is A-40N.
8 0
3 years ago
True or False. Facts are based on observations. *<br><br> True<br> False
nikdorinn [45]

Answer:

TRUE

Explanation:

IM SMART

5 0
3 years ago
Read 2 more answers
Three 7-ohm resistors are connected in parallel with an ideal 12-volt battery. What is the equivalent resistance of the circuit?
Alika [10]

Answer:

Equivalent Resistance of Resistors in Parallel is

1/R = 1/r1 + 1/r2 .....

1/R = 1/7 + 1/7 + 1/7

R= 7/3

R=2.33ohms

7 0
3 years ago
What are the factors that determine the level of harm an introduced chemical has on the environment?
myrzilka [38]

Answer:

they can damage the atmosphere

Explanation:

if you release bad chemicals into the atmosphere it affects the air

3 0
4 years ago
Other questions:
  • A light horizontal spring has a spring constant of 105 N/m. A 2.00 kg block is pressed against one end of the spring, compressin
    5·2 answers
  • What is the average speed of a car that traveled 300.0 miles in 5.5 hours?<br> .
    8·1 answer
  • Which of the following statements is true?
    13·1 answer
  • A 960 kg car initially moving at 30.0 m/s hits a 150-kg deer initially running at 12.0 m/s in the same direction. After the hitt
    7·1 answer
  • How does the energy used by a 100 W lightbulb compare with the energy used by a 40 W lightbulb in a given amount of time? The 10
    9·2 answers
  • The multiple reflection of a single sound <br> wave is a/an
    13·1 answer
  • During what month is there 24 hours of daylight below the antarctic circle
    15·1 answer
  • 20 Points!!!
    13·2 answers
  • Sketch a free body diagram for a hot air balloon which is rising off the ground. Indicate the magnitude of the force by utilizin
    15·1 answer
  • Charlie graduated with a bachelor’s degree in construction management. As he aspires to work in his dad’s construction firm, whi
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!