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
SVEN [57.7K]
2 years ago
7

The emissivity of galvanized steel sheet, a common roofing material, is ε = 0.13 at temperatures around 300 K, while its absorpt

ivity for solar irradiation is αS = 0.65. Find the temperature of a roof constructed of the material on a day when GS = 750 W/m 2 , T[infinity] = 16°C, and h = 7 W/m 2 · K. Assume the bottom surface of the steel is insulated.
Engineering
1 answer:
Step2247 [10]2 years ago
3 0

Answer:

759.99W/m²

Explanation:

Question: If the temperature of the sheet is 77C,what is the incident solar radiation on aday with Tinf= Tsurr= 16°C?

Given

Energy Equation of the Gas

αs * Gs * A + h * A * (T inf - Tg) + εσA (Tsurr⁴- Tg⁴) = 0

Where σ= 5.67 *10^-8 W/m²K⁴ (Stefan-Boltzmann constant)

ε = 0.13 (Emisivity)

αs = 0.65 (Absorptivity for solar radiation)

h = 7W/m²K⁴

Tg = 77 + 273.15K = 350.15K

T inf = 16 + 273.15 = 288.15K

T surr= T inf = 288.15

Substitute the above values in the Gas Equation, we have

0.65 * Gs * A + 7 * A * (288.15 - 350.15) + 0.13 * 5.67 * 10^-8 * A * (288.15⁴ - 350.15⁴) = 0

0.65 * Gs * A = - 7 * A * (288.15 - 350.15) - 0.13 * 5.67 * 10^-8 * A * (288.15⁴ - 350.15⁴)

A cancels out, so we are left with

0.65 * Gs = - 7 * (288.15 - 350.15) - 0.13 * 5.67 * 10^-8 * (288.15⁴ - 350.15⁴)

0.65Gs = 434 - 0.7372 * 10^-8(−8,137,940,481.697)

0.65Gs = 434 + 0.7372 * 81.37940481697

0.65Gs = 493.992897231070284

Gs = 493.992897231070284/0.65

Gs = 759.9890726631850

Gs = 759.99W/m² ------- Approximated

You might be interested in
How many types of arcs do we have in AutoCad? O a.9 O b. 10 Oc. 12 O d. 11​
Dmitry [639]

Answer:

Letter D

Explanation:

AutoCAD provides eleven different ways to create arcs. The different options are used based on the geometry conditions of the design. To create an arc, you can specify various combinations of center, endpoint, start point, radius, angle, chord length, and direction values.

8 0
3 years ago
Read 2 more answers
All brake lights are dimmer than normal. Technician A says that bad bulbs could be the cause. Technician B says that high resist
yarga [219]

Answer:

All Brake lights are dimmer than normal because high resistance in the brake switch could be the cause according to Technician B.

Explanation:

According to Technician A

When the bulb is faulty then no current will flow through bulb and it will be open circuit.So no light will produce in bulb .

According to Technician B

When a high resistance inserted in series  circuit the voltage across each resistance is reduced and this cause the light glow dimly.

Formula of resistance in series circuit

Rt=r1+r2+r3......

5 0
3 years ago
The Torricelli's theorem states that the (velocity—pressure-density) of liquid flowing out of an orifice is proportional to the
Sergeeva-Olga [200]

Answer:

The correct answer is 'velocity'of liquid flowing out of an orifice is proportional to the square root of the 'height'  of liquid above the center of the orifice.

Explanation:

Torricelli's theorem states that

v_{exit}=\sqrt{2gh}

where

v_{exit} is the velocity with which the fluid leaves orifice

h is the head under which the flow occurs.

Thus we can compare the given options to arrive at the correct answer

Velocity is proportional to square root of head under which the flow occurs.

4 0
3 years ago
Technician A says high resistance causes an increase in current flow. Technician B says a higher than
Kryger [21]

The correct statement is: a higher than a normal voltage drop could indicate high resistance. Technician B is correct.

<h3>Ohm's law</h3>

Ohm's law states that the current flowing through a metallic conductor is directly proportional to the voltage provided all physical conditions are constant. Mathematically, it is expressed as

V = IR

Where

V is the potential difference

I is the current

R is the resistance

<h3>Technician A</h3>

High resistance causes an increase in current flow

V = IR

Divide both side by I

R = V / I

Thus, technician A is wrong as high resistance suggest low current flow

<h3>Technician B</h3>

Higher than normal voltage drop could indicate high resistance

V = IR

Thus, technician B is correct as high voltage indicates high resistance

<h3>Conclusion </h3>

From the above illustration, we can see that technician B is correct

Learn more about Ohm's law:

brainly.com/question/796939

8 0
2 years ago
Suppose values is a sorted array of integers. Give pseudocode that describes how a new value can be inserted so that the resulti
Novosadov [1.4K]

Answer:

insert (array[] , value , currentsize , maxsize )

{

   if maxsize <=currentsize

  {

      return -1

  }

  index = currentsize-1

  while (i>=0 && array[index] > value)

  {

      array[index+1]=array[index]

      i=i-1

  }

 

  array[i+1]=value

  return 0

}

Explanation:

1: Check if array is already full, if it's full then no component may be inserted.

2: if array isn't full:

  • Check parts of the array ranging from last position of range towards initial range and determine position of that initial range that is smaller than the worth to be inserted.  
  • Right shift every component of the array once ranging from last position up to the position larger than the position at that smaller range was known.
  • assign new worth to the position that is next to the known position of initial smaller component.
7 0
2 years ago
Other questions:
  • How are isometric drawings and orthographic drawings similar?
    10·1 answer
  • A geothermal heat pump absorbs 15 KJ/s of heat from the Earth 15 m below a house. This heat pump uses a 7.45 kJ/s compressor.
    14·2 answers
  • The best way to become a better reader is to study longer and harder in every subject. engage in a variety of extracurricular ac
    5·2 answers
  • In the given circuit, V(t)=12cos(2000t+45)V, R1=R2=2Ω, L1=L2=L3=3mH and C1=250μF. You are required to find the Thevenin equivale
    7·1 answer
  • Water is contained in a rigid vessel of 5 m3 at a quality of 0.8 and a pressure of 1 MPa. If the pressure is reduced to 270.3 kP
    9·1 answer
  • Write multiple if statements
    5·1 answer
  • Fluid systems can distribute pressure unequally to all points in a system.<br><br> True<br> False
    15·1 answer
  • Tech a says you should push the wrench when braking a fastener loose. Tech b says that you should pull the wrench when braking a
    6·1 answer
  • a motor has torque of 200 nm if i motors attached to an arm with a length of 25 cm and a string is too attached to the end appro
    13·1 answer
  • Which term describes the lowest of a foundation?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!