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
meriva
3 years ago
11

1 Item 1 Item 1 1.25 points circular ceramic plate that can be modeled as a blackbody is being heated by an electrical heater. T

he plate is 30 cm in diameter and is situated in a surrounding ambient temperature of 15°C where the natural convection heat transfer coefficient is 12 W/m2·K. If the efficiency of the electrical heater to transfer heat to the plate is 80%, determine the electric power that the heater needs to keep the surface temperature of the plate at 180°C
Physics
1 answer:
Elena L [17]3 years ago
6 0

Answer:

174.85 W

Explanation:

Area of plate = 3.14 x (15x 10⁻²)²

= 706.5 x 10⁻⁴ m²

heat being radiated by convection = 12 x 706.5 x 10⁻⁴ ( 180 - 15 )

= 139.88 W. This energy needs to be fed by heat source to maintain a constant temperature of 180 degree.

If power of electric source is P

P x .8 = 139.88

P = 139.88 / .8

= 174.85 W

You might be interested in
Why is it more helpful to know a tornadoes velocity rather than its speed
victus00 [196]
So you not only know<span> how fast it is going, but where it is going.</span>
5 0
3 years ago
Read 2 more answers
An uncovered pot of soup is simmering on a stove, and there are water droplets on the wall above the back of the stove. what seq
Lera25 [3.4K]
The answer is vaporization, then condensation.

Here is a set of flash card that can help with this subject.
5 0
4 years ago
Read 2 more answers
which of these best dscribes Earth's mantle? A. most dense layer, consists of the outer and inner parts B. thinnest under the oc
stich3 [128]

C. middle layer, density increases with depth as pressure increases

Explanation:

The mantle is the middle layer of the earth. It's density increases with depth as pressure increases.

  • Based on the compositional division of the earth, our blue planet is divided into crust, mantle and the core.
  • The crust is the lightest and the outermost layer of the earth.
  • The mantle is the middle layer. Its density lies between that of the core and crust.
  • The mantle is the largest layer and density increases with depth here.
  • The core is a metallic ball. It is the most dense part of the earth.

Learn more:

Mantle brainly.com/question/10758534

#learnwithBrainly

6 0
3 years ago
What do wind and moving water have in common? Select one: They both have electrical energy They both have elastic potential ener
ozzi
They both have kinetic energy because they are both moving and have force.
Hope this helped! :)

7 0
3 years ago
A spotlight on the ground shines on a wall 12 m away. If a man 2 m tall walks from the spotlight toward the building at a speed
gregori [183]

Answer:

the rate of the change of the length of the shadow is - 0.8625 m/s.

The negative(-) sign means the length of the shadow decreases at a rate of 0.8625 m/s.

Explanation:

Given the data in the question;

Let x represent the man's distance from building,

initially x = 1m2

dx/d t= -2.3 m/s

Also Let y represent shadow height

so we determine dy/dt when x is 4m from the building

form the image description of the problem, we see two-like triangles with the same base and height ratios

so

 2 / (12-x) = y / 12

24 = y(12 - x )

y = 24 / (12-x)

dy/dt = 24/(12-x)² × dx/dt

Now at x = 4,

we substitute

dy/dt will be;

⇒ 24/(12 - 4)² × -2.3

= 24/64 - 2.3

= 0.375 × -2.3

dy/dt = - 0.8625 m/s

Therefore, the rate of the change of the length of the shadow is - 0.8625 m/s.

The negative(-) sign means the length of the shadow decreases at a rate of 0.8625 m/s.

5 0
3 years ago
Other questions:
  • Electron groups consist of which of the following? A.Bonded pairs of electrons B.Lone-pair electrons C.Any atom that's an ion D.
    6·1 answer
  • Which of the following is true about parallax?
    14·2 answers
  • Male Rana catesbeiana bullfrogs are known for their loud mating call. The call is emitted not by the frog's mouth but by its ear
    14·1 answer
  • Which circuit-A or B-represents a series circuit? Explain your answer.
    5·1 answer
  • An automobile can be considered to be mounted on four identical springs as far as vertical oscillations are concerned. The sprin
    11·1 answer
  • Which astronomer proved that the planets of our solar system move in elliptical orbits? A. Kepler B. Copernicus C. Ptolemy D. Ga
    5·2 answers
  • If the half-life of a decaying isotope is 10 years, which statement is true after<br> 10 years?
    13·1 answer
  • What a Cell Wall can some tell me
    14·1 answer
  • When iron pipes come in contact with water and oxygen, iron transfers electrons to the oxygen molecules. Which
    8·1 answer
  • Why do we use days and hours instead of hours?<br>​
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!