10

Thermopane window is constructed, using two layers of glass 4.0 mm thick, separated by an air space of 5.0 mm.

Bond [772]

To solve this problem it is necessary to apply the concepts related to rate of thermal conduction

$\frac{Q}{t} = \frac{kA\Delta T}{d}$

The letter Q represents the amount of heat transferred in a time t, k is the thermal conductivity constant for the material, A is the cross sectional area of the material transferring heat, $\Delta T$ , T is the difference in temperature between one side of the material and the other, and d is the thickness of the material.

The change made between glass and air would be determined by:

$(\frac{Q}{t})_{glass} = (\frac{Q}{t})_{air}$

$k_{glass}(\frac{A}{L})_{glass} \Delta T_{glass} = k_{air}(A/L)_{air} \Delta T_{air}$

$\Delta T_{air} = (\frac{k_{glass}}{k_{air}})(\frac{L_{air}}{L_{glass}}) \Delta T_{glass}$

$\Delta T_{air} = (\frac{0.84}{0.0234})(\frac{5}{4}) \Delta T_{glass}$

$\Delta T_{air} = 44.9 \Delta T_{glass}$

There are two layers of Glass and one layer of Air so the total temperature would be given as,

$\Delta T = \Delta T_{glass} +\Delta T_{air} +\Delta T_{glass}$

$\Delta T = 2\Delta T_{glass} +\Delta T_{air}$

$20\°C = 46.9\Delta T_{glass}$

$\Delta T_{glass} = 0.426\°C$

Finally the rate of heat flow through this windows is given as,

$\Delta {Q}{t} = k_{glass}\frac{A}{L_{glass}}\Delta T_{glass}$

$\Delta {Q}{t} = 0.84*24*10 -3*0.426$

$\Delta {Q}{t} = 179W$

Therefore the correct answer is D. 180W.

3 0

3 years ago

Write an equation for the magnetic field vector b generated by the current at an arbitrary point in terms of i, the length eleme

Lubov Fominskaja [6]

The magnetic field vector B generated by the current at an arbitrary point in terms of i, the length element dl, and the vector for the distance r from dl to the point is given by the equation dB = μ0/4 π ∫ (dl x r)/r $r^{3}$

<h3>Biot – Savart Law and its Applications:</h3>

The Biot – Savart Law gets its name from Jean-Baptiste Biot and Felix Savart. This is a formula that describes the relationship between force, displacement, and velocity. It plays a huge role in the branch of electromagnetism. This law is used to derive the equation between the magnetic field which is produced due to the flow of a constant electric current.

The equation of Biot – Savart law is

dB = μ0/4 π ∫ {(idl sinΦ)/r2}

Here,

I is the current,

dl is the small length of the wire. As the direction of this length is along the current hence it forms the vector idl.

r is the position vector of the point in question which is drawn from the current element and

Φ is the angle between the two.

<h3>Applications of Biot – Savart Law </h3>

• It helps in the calculation of magnetic field in an infinitely long straight wire with constant current,

• Calculation of magnetic field in the center of current carrying arc can be done by this,

• To calculate the magnetic field along the axis of a circular current carrying coil, this law can be used.

To know more about Biot - Savart Law visit:

brainly.com/question/14950341

#SPJ4

3 0

1 year ago

PLZ HELP ME!!!!!!!!!!!!!!!!!!!!!!!!!!!<br> What is a front?

Shkiper50 [21]

Answer:

in computer and writing context it is many styles of writing that you can make the text look like. I.E: <em>helllo </em>hello

Explanation:

A font is the combination of typeface and other qualities, such as size, pitch, and spacing. For example, Times Roman is a typeface that defines the shape of each character. Within Times Roman, however, there are many fonts to choose from -- different sizes, italic, bold, and so on.

Mark me the brainliest plz

4 0

3 years ago

Read 2 more answers

The distance between Miami and Oriando is about 220 miles .A pilot flying from

krok68 [10]

100/1=x/0.985, 98.5=x. So the distance from Orlando is 220-98.5=121.5miif he adjusts, he has 98.5 miles more to do, plus 121.5 miles he already did, the flight is 1.25 mi farther

6 0

4 years ago

The carnival ride has a 2.0m radius and rotates 1.1 times persecond.

Lady_Fox [76]

Answer:

a) v = 13.8 m / s , b) a = 95.49 m / s² , c) a force that goes to the center of the carnival ride and d) μ = 0.10

Explanation:

For this exercise we will use the angular kinematics relationships and the equation that relate this to the linear kinematics

a) reduce the magnitudes to the SI system

w = 1.1 rev / s (2pi rad / 1rev) = 6.91 rad / s

The equation that relates linear and angular velocity is

v = w r

v = 6.91 2

v = 13.8 m / s

b) centripetal acceleration is given by

a = v² / r = w² r

a = 6.91² 2

a = 95.49 m / s²

c) this acceleration is produced by a force that goes to the center of the carnival ride

d) Here we use Newton's second law

fr -W = 0

fr = W

μ N = mg

Radial shaft

N = m a

N = m w² r

μ m w² r = m g

μ = g / w² r

μ = 9.8 / 6.91² 2

μ = 0.10

3 0

4 years ago