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
patriot [66]
3 years ago
5

A cartridge electrical heater is shaped as a cylinder of length L=200mm and outer diameter D=20 mm. Under normal operating condi

tions the heater dissipates 2kW while submerged in a water flow that is 20℃ and provides a convection heat transfer coefficient of ℎ = 5000 W/m2K. Neglecting heat transfer from the ends of the heater, determine its surface temperature T???? . If the water flow is in advertently terminated while the heater continues to operate, the heater surface is exposed to air that is also at 20℃ but for which ℎ = 50 W/m2K. What is the corresponding surface temperature?
Engineering
1 answer:
lara31 [8.8K]3 years ago
3 0

Answer:

T(water)=50.32℃

T(air)=3052.6℃

Explanation:

Hello!

To solve this problem we must use the equation that defines the transfer of heat by convection, which consists of the transport of heat through fluids in this case water and air.

The equation is as follows!

Q=ha(Ts-T\alpha )

Q = heat

h = heat transfer coefficient

Ts = surface temperature

T = fluid temperature

a = heat transfer area

The surface area of ​​a cylinder is calculated as follows

a=\pi D(\frac{D}{2} +L)

Where

D=diameter=20mm=0.02m

L=leght=200mm)0.2m

solving

a=\pi (0.02)(\frac{0.02}{2} +0.2)=0.01319m^2

For water

Q=2Kw=2000W

h=5000W/m2K

a=0.01319m^2

Tα=20C

Q=ha(Ts-T\alpha )

solving for ts

Ts=T\alpha +\frac{Q}{ha}

Ts=20+\frac{2000}{(0.01319)(5000)} =50.32C

for air

Q=2Kw=2000W

h=50W/m2K

a=0.01319m^2

Tα=20C

Ts=20+\frac{2000}{(0.01319)(50)}=3052.6C

You might be interested in
What test should be performed on abrasive wheels
Svet_ta [14]

Answer:

before wheel is put on it should be looked at for damage and a sound or ring test should be done to check for cracks, to test the wheel it should be tapped with a non metallic instrument (I looked it up)

3 0
3 years ago
Read 2 more answers
A Geostationary satellite has an 8kW RF transmission pointed at the earth. How much force does that induce on the spacecraft? (N
soldier1979 [14.2K]

Answer:

The force induced on the aircraft is 2.60 N

Solution:

As per the question:

Power transmitted, P_{t} = 8 kW = 8000 W

Now, the force, F is given by:

P_{t} = Force(F)\times velocity(v) = Fv               (1)

where

v = velocity

Now,

For a geo-stationary satellite, the centripetal force, F_{c} is provided by the gravitational force, F_{G}:

F_{c} = F_{G}

\frac{mv^{2}}{R} = \frac{GM_{e}m{R^{2}}

Thus from the above, velocity comes out to be:

v = \sqrt{\frac{GM_{e}}{R}}

v = \sqrt{\frac{6.67\times 10^{- 11}\times 5.979\times 10^{24}}{42166\times 10^{3}}} = 3075.36 m/ s

where

R = R_{e} + H

R = \sqrt{GM_{e}(\frac{T}{2\pi})^{2}}

where

G = Gravitational constant

T = Time period of rotation of Earth

R is calculated as 42166 km

Now, from eqn (1):

8000 = F\times 3075.36

F = 2.60 N

6 0
3 years ago
____ grinders are used to grind diameters, shoulders, and faces much like the lathe is used for turning, facing, and boring oper
skelet666 [1.2K]

Answer:

Cylindrical

Explanation:

<em>A cylindrical grinder </em><em>is a tool for shaping the exterior of an item. Although cylindrical grinders may produce a wide range of forms, the item must have a central axis of rotation. Shapes such as cylinders, ellipses, cams, and crankshafts are examples of this.</em><em> Cylindrical grinding</em><em> machines are specialized grinding machines that are used to process cylinders, rods, and similar workpieces. The cylinders revolve in one direction between two centers, while the grinding wheel or wheels are close together and rotate in the other direction.</em>

8 0
2 years ago
An engineering firm just lost one of their larger customers. The firm president says that the solution to this problem is to fir
Shkiper50 [21]

Answer:

The engineers disagreed because their jobs were on the line

The ethical factors are:

The reason for the customer dumping the business is yet to be figured out

The need to keep cost to the lowest ebb in order to keep maintain profitability at the expense of employees' welfare

The are several ways of growing customer base which  are yet to be exploited.

Explanation:

The engineers disagree because there is no direct connection between the company's loss of the customer and their proposed layoff of the engineers,at least no one strong evidence has been given by the president.

The ethical factors inherent in this case are as follows:

The reason for the customer dumping the business is yet to be figure out

The need to keep cost to the lowest ebb in order to keep maintain profitability.

The are several ways of growing customer base which  are yet to be exploited.

There is  a need for a fact-finding exercise to establish the main motive behind losing such customer,without which the company can run into more troubles in future,otherwise the company would keep firing its good hands each time a customer dumps it.

Also,the president had resulted into such decision in order to maintain company's margins,where then lies ethics of welfare economics?Welfare economics is about looking beyond margins and looking at issues from a wider perspective of fulfilling the needs of employees in order for them to put in their best performance,at least by granting them job safety.

The company could have also grown business by investing in new technology that sets it apart from competitors instead of just jumping into the conclusions of sacking employees in a business where the company's strength lies in quality of engineers that it has.

7 0
3 years ago
Two particles have a mass of 7.8 kg and 11.4 kg , respectively. A. If they are 800 mm apart, determine the force of gravity acti
aleksley [76]

Answer:

A) About 9.273 \times 10^{-9} newtons

B) 76.518 newtons

C) 111.834 newtons

Explanation:

A) F_g=\dfrac{GM_1M_2}{r^2} , where G is the universal gravitational constant, M 1 and 2 are the masses of both objects in kilograms, and r is the radius in meters. Plugging in the given numbers, you get:

F_g=\dfrac{(6.67408 \times 10^{-11})(7.8)(11.4)}{(0.8)^2}\approx 9.273 \times 10^{-9}

B) You can find the weight of each object on Earth because you know the approximate acceleration due to gravity is 9.81m/s^2. Multiplying this by the mass of each object, you get a weight for the first particle of 76.518 newtons.

C) You can do a similar thing to the previous particle and find that its weight is 11.4*9.81=111.834 newtons.

Hope this helps!

3 0
3 years ago
Other questions:
  • What is the heat flux (W/m2) to an object when subjected to convection heat transfer environment given: 24 °C = the surface temp
    10·1 answer
  • Are spheroidized steels considered as composite? If so, what is the dispersed phase a)- No b)- Yes, Chromium Carbides c)- Yes, I
    12·1 answer
  • One kilogram of air, initially at 5 bar, 350 K, and 3 kg of carbon dioxide (CO2), initially at 2 bar, 450 K, are confined to opp
    14·1 answer
  • If changing employment what do you need to do? Email your new employer information to the Deptartment of International Graduate
    5·1 answer
  • A 4-pole, 3-phase induction motor operates from a supply whose frequency is 60 Hz. calculate: 1- the speed at which the magnetic
    10·1 answer
  • PLEASE HELP!<br> I'm in the middle of a test and the teacher didn't go over the material!
    10·1 answer
  • Determine the resistance of 100m of copper cable whose cross-sectional area is 1.5mm2​
    6·1 answer
  • 48/64 reduced to its lowest term
    5·2 answers
  • What is anthropology? Discuss the type of anthropology?
    5·2 answers
  • Select four items that an industrial engineer must obtain in order to practice in the field.
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!