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
SCORPION-xisa [38]
3 years ago
7

A composite wall is to be used to insulate a freezer chamber at -350C. Two insulating materials are to be used with conductiviti

es of 0.04 W/mK and 0.1 W/mK. If the outside surface temperature of the inner layer (0.04 W/mK) should not go below zero and if the exposed surface temperature should not go below (the expected wet bulb temperature) 220C determine the insulation thicknesses. The heat gain is to be limited to 10 W/m^2. Also estimate the value of convection coefficient at such a situation. Outside is at 250C.
Engineering
1 answer:
choli [55]3 years ago
7 0

Answer:

thickness1=1.4m

thickness2=2.2m

convection coefficient=0.33W/m^2K

Explanation:

you must use this equation to calculate the thickness:

L=K(T2-T1)/Q

L=thickness

T=temperature

Q=heat

L1=0.04*(0--350)/10=1.4m

L2=0.1(220-0)/10=2.2m

Then use this equation to calculate the convective coefficient

H=Q/(T2-T1)

H=10/(250-220)=0.33W/m^2K

You might be interested in
Comparison of density values determines whether an item will float or sink in water. For each of the values below, determine the
geniusboy [140]

Answer:

a) the object floats

b) the object floats

c) the object sinks

Explanation:

when an object is less dense than in the fluid in which it is immersed, it will float due to its weight and volume characteristics, so to solve this problem we must find the mass and volume of each object in order to calculate the density and compare it with that of water

a)

volumen for a cube

V=L^3

L=1.53in=0.0388m

V=0.0388 ^3=5.8691x10^-5m^3=58.69ml

density=m/v

density=13.5g/58.69ml=0.23 g/ml

The wooden block floats  because it is less dense than water

b)

m=111mg=0.111g

density=m/v

density=0.111g/0.296ml=0.375g/ml

the metal paperclip floats   because it is less dense than water

c)

V=0.93cups=220.0271ml

m=0.88lb=399.1613g

Density=m/v

density=399.1613/220.027ml=1.8141g/ml

the apple sinks   because it is  denser than water

4 0
3 years ago
2. The device that varies incoming line pressure using centrif-
Kryger [21]

Answer:

I believe  reverse boost valve.

3 0
3 years ago
Identify the phase of the design process illustrated in the following scenario, and justify its importance. Kristin has recently
zaharov [31]

Answer:

The design process is at the verify phase of Design for Six Sigma

Explanation:

In designing for Six Sigma, DFSS, is a product or process design methodology of which the goal is the detailed identification of the customer business needs by using measurements tools such as statistical data, and incorporating the identified need into the created product which in this case is the hydraulic robot Kristin Designed

Implementation of DFSS follows a number of stages that are based on the DMAIC (Define - Measure - Analyze - Improve) projects such as the DMADV which stand for define - measure - analyze - verify

Therefore, since Kristin is currently ensuring that the robot is working correctly and meeting the needs of her client the design process is at the verify phase.

5 0
3 years ago
Given: A graphite-moderated nuclear reactor. Heat is generated uniformly in uranium rods of 0.05m diameter at the rate of 7.5 x
sineoko [7]

Answer:

The maximum temperature at the center of the rod is found to be 517.24 °C

Explanation:

Assumptions:

1- Heat transfer is steady.

2- Heat transfer is in one dimension, due to axial symmetry.

3- Heat generation is uniform.

Now, we consider an inner imaginary cylinder of radius R inside the actual uranium rod of radius Ro. So, from steady state conditions, we know that, heat generated within the rod will be equal to the heat conducted at any point of the rod. So, from Fourier's Law, we write:

Heat Conduction Through Rod = Heat Generation

-kAdT/dr = qV

where,

k = thermal conductivity = 29.5 W/m.K

q = heat generation per unit volume = 7.5 x 10^7 W/m³

V = volume of rod = π r² l

A = area of rod = 2π r l

using these values, we get:

dT = - (q/2k)(r dr)

integrating from r = 0, where T(0) = To = Maximum center temperature, to r = Ro, where, T(Ro) = Ts = surface temperature = 120°C.

To -Ts = qr²/4k

To = Ts + qr²/4k

To = 120°C + (7.5 x 10^7 W/m³)(0.025 m)²/(4)(29.5 W/m.°C)

To = 120° C + 397.24° C

<u>To = 517.24° C</u>

5 0
3 years ago
PLEASEE HELP.!! ILL GIVE BRAINLIEST.!! *EXTRA POINTS* DONT SKIP:((
Trava [24]

Answer:

16

Explanation:

Have a good day my friend

8 0
3 years ago
Read 2 more answers
Other questions:
  • True or false? Engineering degree programs and engineering technology degree programs have a different requirements
    9·1 answer
  • Valves on steam lines are commonly encountered and you should know how they work. For most valves, the change in velocity of the
    10·1 answer
  • For a steel alloy it has been determined that a carburizing heat treatment of 11-h duration will raise the carbon concentration
    12·1 answer
  • Anyone know sebastian from bb
    8·1 answer
  • A water reservoir contains 108 metric tons of water at an average elevation of 84 m. The maximum amount of electric energy that
    5·1 answer
  • Draw a flowchart to represent the logic of a program that allows the user to enter values for the current year and the user’s bi
    14·1 answer
  • Why is communication one of the most important aspects of an engineer’s job?
    7·2 answers
  • A smooth ceramic sphere (SG 5 2.6) is immersed in a fl ow of water at 208C and 25 cm/s. What is the sphere diameter if it is enc
    11·1 answer
  • Which of the following is the class of ingredient which is the base for most baked items?
    5·1 answer
  • A team of engineers is working on a design to increase the power of a hydraulic lever. They have brainstormed several ideas. Whi
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!