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
Goshia [24]
3 years ago
8

A 2.5 m-high, 4-m-wide, and 80-cm-thick wall of a house has a thermal resistance of 0.0125°c/W. The thermal conductivity of the

wall is (a) 3.2 W/mK (b) 4.8 W/m-K (c) 6.4 W/m-K (d) 1.6 W/m-K (e) 32 W/m-K
Engineering
1 answer:
ohaa [14]3 years ago
5 0

Answer:

The correct answer is part 'c': 6.4 W/m-K

Explanation:

We know that the thermal resistance of a wall is given by

R_{wall}=\frac{L}{kA}

where,

L = thickness of wall

k = thermal conductivity of wall

A = Surface area of wall

Applying values we get

k=\frac{L}{R_{wall}A}

k=\frac{80\times 10^{-2}}{0.0125\times 2.5\times 4}\\\\\therefore k=6.4W/mK

You might be interested in
Liberty Autos recognizes that it has some customers who like roomy SUVs, while others like more compact versions. Liberty design
Elina [12.6K]

Answer:

segmenting the market

Explanation:

Liberty Auto is dividing its customers into smaller groups based on different characteristics & based on their needs they will optimize their products and then advertise to different customers.

3 0
4 years ago
The four important principles of flight are lift, drag, thrust, and _____.
lbvjy [14]

Answer:

gravity force or weight

6 0
3 years ago
why did my dirtbike just stop when i was riding it, and now when i start it it sounds like it has a knock, and wont stay running
chubhunter [2.5K]

Answer: check the engines i swear if ur talking about an actual bike im gonna be so embarrassed lma0

7 0
3 years ago
Read 2 more answers
The water behind Hoover Dam in Nevada is 221 m higher than the Colorado River below it. At what rate must water pass through the
dexar [7]

Answer:

23.06262m^3/s

Explanation:

The volume flow rate of the water is determined from the needed power output and the elevation difference:

Where, height (h) =221m, power(w)=50MW=50*10^6w

Density of water (ρ)=1000kg/m^3

Efficiency of turbine(η)=100%=1

V=W/ρηgh

=50*10^6m^3/(1)*(1000)*(9.81)*(221)s=23.06262m^3/s

3 0
3 years ago
While walking across campus one windy day, an engineering student speculates about using an umbrella as a "sail" to propel a bic
makvit [3.9K]

Answer:

Given data:\\While walking across campus one windy day\\Frontal area, \(A=0.3 m ^{2}\)\\Wind speed \(V=24 Km / hr\)\\The drag coefficient \(C_{D, b}=1.2\)\\The combined mass \(m=75 kg\)\\Umbrella diameter, \(D=1.22 m\)\\Velocity of wind \(V=24 \frac{ km }{ hr }\)\\The rolling resistance \(C_{R}=0.75 \%\)

Solution:

Note: Refer the diagram

Basic equation:\\'s law of motion: \(\sum F_{x}=m a_{x}\)\\Lift coefficient, \(C_{L}=\frac{F_{L}}{\frac{1}{2} \rho V^{2} A_{p}}\)\\Drag coefficient, \(C_{D}=\frac{F_{D}}{\frac{1}{2} \rho V^{2} A_{p}}\)

From force balance equation:\\\(\sum F_{x}=F_{D}-F_{R}=0\)\\But \(F_{D}=\left(C_{D, \alpha} A_{u}+C_{D, B} A_{b}\right) \frac{1}{2} \rho\left(V_{\nu}-V_{b}\right)^{2}\)\(F_{R}=C_{R} m g\)\\Area of the Umbrella \(A_{u}=\frac{\pi D_{u}^{2}}{4}\)\(A_{x}=\frac{\pi \times 1.22^{2}}{4} m ^{2}\)\(A_{v}=1.17 m ^{2}\)

Drag coefficient data for selected objects table at

Hemisphere (open end facing flow), C_{D, x}=1.42

Substituting all parameters,

\begin{aligned}&F_{R}=0.0075 \times 75 \times 9.81\\&F_{R}=5.52 N\end{aligned}

Then,

\begin{aligned}&V_{b}=V_{w}-\left[\frac{2 F_{R}}{\rho\left(C_{D, w} A_{w}+C_{D, B} A_{b}\right)}\right]^{\frac{1}{2}} \dots\\&V_{w}=24 \times 1000 \times \frac{1}{3600}\\&V_{w}=6.67 \frac{ m }{ s }\end{aligned}

And the equation becomes,

\begin{aligned}&V_{b}=6.67-\left[\frac{2 \times 5.52}{1.23(1.42 \times 1.17+1.2 \times 0.3)}\right]^{\frac{1}{2}}\\&V_{b}=6.67-2.11\\&V_{b}=4.56 \frac{ m }{ s }\end{aligned}

Thus the floyds travels at 68.3^{\circ}wind speed.

7 0
4 years ago
Other questions:
  • How does the invention of electrical lights and automobiles impact the world today? Explain. (1 paragraph minimum)
    11·1 answer
  • Estimate the magnitude of the force, in lbf, exerted on a 12-lb goose in a collision of duration 10^-3s with an airplane taking
    15·1 answer
  • The rolling process is governed by the frictional force between the rollers and the workpiece. The frictional force at the entra
    5·1 answer
  • Which of following unit cell has the smallest atomic packing factor? (a) BCC unit cell (b) FCC unit cell (c) SC unit cell (d) HC
    5·1 answer
  • Before charging a system that has been opened for service
    11·1 answer
  • You are hired as the investigators to identify the root cause and describe what should have occurred based on the following info
    9·1 answer
  • (a) calculate the moment at point "c", where point "c" is the square 3'' below the centroid
    13·1 answer
  • A countinous shot that sense, flows well, and is understanable and pleasant to look at
    13·1 answer
  • 10. What type of sealant would be best for sealing<br> between machined surfaces of rigid castings?
    10·1 answer
  • Find I with superposition technique.
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!