Please help me overall in this homework. I did number 1 but the others I do not get
ME 201 Fall 2015 - Homework 8
1. Read sections 16.2 ? 16.4 in the book.
Write the following equations for ? , in [kJ/s], using the variables at right.
A. Conduction heat transfer
B. Convection heat transfer
C. Radiation heat transfer A = area
h = heat transfer coefficient
? = emissivity
k = thermal conductivity
? = Stefan-Boltzmann constant
L = distance
T1, T2 = temperatures
?T = temperature difference 2. A wall of area A is made of 20-mm thick decorative panel (k=1.0 W/m°C) and 200-mm thick brick
(k=2.0 W/m°C). On a winter day, the inner room air temperature was maintained at 21°C, external
air temperature was -19°C, the convective heat transfer coefficient was 25 W/m2K on the inside and
100W/m2K on the outside, and the total heat loss was found to be 5.2 kW. Neglect radiation.
D. Draw the thermal resistance circuit showing all thermal resistors between the inner and
Write an equation for total thermal resistance. Which of the walls, brick or panel, will
have a greater temperature gradient?
Calculate the area A of the wall in m2.
Calculate the temperatures of the left, middle, and outer surfaces, assuming the wall
area A = 22m2 and other conditions similar to above. 3. Three friends spend an hour trick-or-treating outside on a windy 0°C Halloween night. The costumes:
C: Iron-man (2mm-thick, uninsulated, molded Aluminum)
Captain Jack Sparrow (2mm-thick felt fabric, k = 0.08 W/mK)
Giant banana (2mm-thick polyethylene plastic, (k = 0.45 W/mK) How many candy bars must each eat to recover the heat energy lost during the time spent outside?
Assumptions: neglect radiation heat transfer
a person can be modeled as a vertical cylinder 0.3m in diameter, 1.5m tall
costumes fully contact the skin (constant skin surface temp = 32°C)
candy bars contain 250 Calories. (1 Cal = 1 kcal = 4.1868 kJ)
convection heat transfer coefficient, h = 14W/m2K
Hint: use the thermal resistance method.
4. NASA?s New Horizons spacecraft flew by the planet Pluto this past summer. Suppose the outer
surface of the spacecraft has an emissivity of 0.8 and a solar absorptivity of 0.3. Consider the
following two conditions:
B. At launch, solar radiation is incident on the craft at a rate of 1320 W/m2.
At its current position near Pluto, solar radiation is only 1.5 W/m2. Determine the surface temperature of the spacecraft in each of the two cases, when the radiation
emitted equals the solar energy absorbed.
This question was answered on: Sep 13, 2020Buy this answer for only: $15
This attachment is locked
Pay using PayPal (No PayPal account Required) or your credit card . All your purchases are securely protected by .
About this QuestionSTATUS
Sep 13, 2020EXPERT
GET INSTANT HELP/h4>
We have top-notch tutors who can do your essay/homework for you at a reasonable cost and then you can simply use that essay as a template to build your own arguments.
You can also use these solutions:
- As a reference for in-depth understanding of the subject.
- As a source of ideas / reasoning for your own research (if properly referenced)
- For editing and paraphrasing (check your institution's definition of plagiarism and recommended paraphrase).
NEW ASSIGNMENT HELP?
Order New Solution. Quick Turnaround
Click on the button below in order to Order for a New, Original and High-Quality Essay Solutions. New orders are original solutions and precise to your writing instruction requirements. Place a New Order using the button below.
WE GUARANTEE, THAT YOUR PAPER WILL BE WRITTEN FROM SCRATCH AND WITHIN A DEADLINE.