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
maria [59]
3 years ago
10

A sphere is assumed to have the properties of water and has an initial heat generation 46480 W/m^3 How much should the heat gene

ration term be lowered, if the maximum temperature at the center of the spherical geometry is to be limited to 360 Kelvin? The radius of the sphere is 0.1m ambient air temperature is 25 C. Convert the resulting heat generation to Food Calories per hour
Engineering
1 answer:
Verdich [7]3 years ago
3 0

Answer:

Resulting heat generation, Q = 77.638 kcal/h

Given:

Initial heat generation of the sphere, Q_{Gi} = 46480 W/m^{3}

Maximum temperature, T_{m} = 360 K

Radius of the sphere, r = 0.1 m

Ambient air temperature, T = 25^{\circ}C = 298 K

Solution:

Now, maximum heat generation, Q_{m} is given by:

T_{m} = \frac{Q_{m}r^{2}}{6K} + T                     (1)

where

K = Thermal conductivity of water at T_{m} = 360 K = 0.67 W/m^{\circ}C

Now, using eqn (1):

360 = \frac{Q_{m}\times 0.1^{2}}{6\times 0.67} + 298

Q_{m} = 24924 W/m^{3}

max. heat generation at maintained max. temperature of 360 K is 24924W/m^{3}

For excess heat generation, Q:

Q = (Q_{Gi} - Q_{m})\times volume of sphere, V

where

V = \frac{4}{3}\pi r^{3}

Q = (46480 - 24924)\times \frac{4}{3}\pi\0.1^{3} = 21556\times \frac{4}{3}\pi\0.1^{3} W/m^{3}

Q = 90.294 W

Now, 1 kcal/h = 1.163 W

Therefore,

Q = \frac{90.294}{1.163} = 77.638 kcal/h

You might be interested in
Why did my dad leave me yesterday like whatd i do?
Vsevolod [243]

Answer:

hmm i would try calling him. ask your mom or other adults where he is!

Explanation:

hope you get help soon!

4 0
3 years ago
Who is responsible for keeping your facility in compliance <br>​
inessss [21]
<h2>Answer:</h2><h2>The safety manager is usually the person responsible for ensuring whether the company is in compliance with the OSHA employer requirements . These type of requirements include; Fatal accidents that result in the hospitalisation of three or more employees,must be reported to the OSHA nearest office within 8 hours.</h2>

4 0
3 years ago
Write a python program to apply this:
lakkis [162]

Answer:

# Initialize a dictionary with the keys

contestants = {"Darci Lynne":0, "Angelica Hale":0, "Angelina Green":0};

# Repeatedly prompt the user for a contestant name to vote for

while True:

 

  # Prompting user for contestant name

  cName = input("Enter contestant name to vote: ");

 

  # Checking for Done

  if cName.lower() == "done":

      break;

 

  # Checking in dictionary

  if cName in contestants.keys():

      # Updating vote value

      contestants[cName] += 1

  # New entry

  else:

      contestants[cName] = 1

 

# Printing header

print("\n%-20s %-15s\n" %("Contestant Name", "Votes Casted"))

# Printing results

for contestant in contestants:

  print("%-23s %-15d" %(contestant, contestants[contestant]))

8 0
3 years ago
A thin rim with a mean diameter of 1.2 m cross-section of 15 mm x 200 mm is subjected to an internal pressure of 10 MPa and rota
Soloha48 [4]

Answer:

The net centrifugal force over the rim is 30000N, the radial stress is 397887 Pa and the total change in diameter is 4.98 mm.

Explanation:

Lets first calculate the force in the rim due to the centrifugal force. For doing this we may assume that the centrifugal force is constant along with thick because of the thin thick.

Fc = m.ω^2/R

Where m is the mass, w the angular speed and R the mean radius.  The mass is computing by the rim density and its volume:

m=p.V

m=p*(A*R)

Where A is the cross-sectional area in meters:

m=((0.015m*0.200m)*0.6m)*(7800 kg/m^3)=28.08 kg

The angular speed in rad/s is:

ω = 800r/m . 1m/60s = 133.33 r/s

Thus the centrifugal force is:

Fc = (28.08 kg)*(133.33 rad/s)^2*(0.6m) = 299505N = 30000N

Note that the calculating value is the net contribution to the whole rim but the centrifugal force is distributed along the rim's external area:

fc = Fc / (2π .R .b)

Where b is rim's with equal to 200mm :

fc = 300000 N / (2π*0.6m*0.2m) = 397887 N/m^2

The centrifugal force can be taken as internal pressure:

Pfc = 397887 N/m^2 = 3978787 Pa

As both pressures act expanding the rim it can be summed:

Pt=Pi+Pfc

Pt = 10MPa+397887Pa= 10000000Pa+397887Pa= 10397887Pa

Then for a thinner thick the stress is calculated by:

Pt*d =2σr*t

Take into account that the stress σr is over the radial direction. Then solving for o and by replacing the total pressure:

σr = Pt.d/(2*t)

σr = 10397887 Pa / (2*0.015m*0.2m) = 415915480Pa = 415MPa

We know that the radial specific deformation ε is:

σr = E / εr

εr = σr / E

For a young modulus of 200GPa:

εr = 415MPa / 200GPa

εr = 415MPa / 200000MPa=0.002075

By definition the specific deformation is written in terms of the total change in the radius:

εr = Δr / R

Δr = R / εr =0.002075 * 1.2 m = 0.00249m

As we need the change in diameter:

Δd = 2Δr =0.00498m= 4.98mm [/tex]

5 0
3 years ago
A spherical container made of steel has 20 ft outer diameter and wal thickness of 1/2 inch. Knowing the internal pressure is 50
anastassius [24]

Answer:

maximum normal stress = 5975 psi

maximum shear stress = 2987.50 psi

Explanation:

Given data

dia = 20 ft

wall thickness = 1/2 inch

internal pressure  = 50 psi

To find out

the maximum normal stress and the maximum shearing stress

Solution

By the Mohr's circle we will find out shear stress

first we calculate inner radius

i.e. r = (diameter/2) - t

r = (20 × 12 in )/2 - ( 1/2 )

r =  120 - 0.5 = 119.5 inch

Now we find out maximum normal stress by given formula

normal stress = ( internal pressure× r ) / 2 t

normal stress = ( 50×119.5 ) / 2 × 0.5

maximum normal stress = 5975 psi

and minimum normal stress is 0, due to very small radius

and maximum shear stress will be

shear stress = ( maximum normal stress - minimum normal stress ) / 2

shear stress = ( 5975- 0 ) / 2

maximum shear stress = 2987.50 psi

5 0
3 years ago
Other questions:
  • Signal generator‘s internal impedance is purely resistive and has an open-circuit voltage of 3.5 V. When the generator is loaded
    11·1 answer
  • Go online and search for information about companies that have been harmed or bankrupted by a disaster. Choose one such company
    11·1 answer
  • Two pressure gauges measure a pressure drop of 16.3 psi (lb/in.2) at the entrance and exit of an old buried pipeline. The origin
    13·1 answer
  • A force of 16,000 will cause a 1 1 bar of magnesium to stretch from 10 to 10.036 . Calculate the modulus of elasticity in . (Ent
    6·1 answer
  • A pipe of 0.3 m outer diameter at a temperature of 160°C is insulated with a material having a thermal conductivity of k = 0.055
    14·1 answer
  • A kite is an airfoil that uses the wind to produce a lift. Held in place by a string, a kite can remain aloft indefinitely. The
    9·1 answer
  • The Acme tool is aligned to the work with: A. A square B. The eye C. An Acme tool gage D. A center gage
    14·1 answer
  • All brake lights are dimmer than normal. Technician A says that bad bulbs could be the cause. Technician B says that high resist
    6·1 answer
  • How do you extablish a chain of dimensions​
    15·1 answer
  • 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
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!