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
Zigmanuir [339]
3 years ago
5

An object of irregular shape has a characteristic length of L = 0.5 m and is maintained at a uniform surface temperature of Ts =

400 K. When placed in atmospheric air at a temperature of T[infinity] = 300 K and moving with a velocity of V = 25 m/s, the average heat flux from the surface to the air is 10,000 W/m2 . If a second object of the same shape, but with a characteristic length of L = 2.5 m, is maintained at a surface temperature of Ts = 400 K and is placed in atmospheric air at T[infinity] = 300 K, what will the value of the average convection coefficient be if the air velocity is V = 5 m/s?.
Physics
1 answer:
goblinko [34]3 years ago
7 0

Answer:

The value of the average convection coefficient is 20 W/Km².

Explanation:

Given that,

For first object,

Characteristic length = 0.5 m

Surface temperature = 400 K

Atmospheric temperature = 300 K

Velocity = 25 m/s

Air velocity = 5 m/s

Characteristic length of second object = 2.5 m

We have same shape and density of both objects so the reynold number will be same,

We need to calculate the value of the average convection coefficient

Using formula of  reynold number for both objects

R_{1}=R_{2}

\dfrac{u_{1}L_{1}}{\eta_{1}}=\dfrac{u_{2}L_{2}}{\eta_{2}}

\dfrac{h_{1}L_{1}}{k_{1}}=\dfrac{h_{2}L_{2}}{k_{2}}

Here, k_{1}=k_{2}

h_{2}=h_{1}\times\dfrac{L_{1}}{L_{2}}

h_{2}=\dfrac{q}{T_{2}-T_{1}}\times\dfrac{L_{1}}{L_{2}}

Put the value into the formula

h_{2}=\dfrac{10000}{400-300}\times\dfrac{0.5}{2.5}

h_{2}=20\ W/Km^2

Hence, The value of the average convection coefficient is 20 W/Km².

You might be interested in
6. A dumb, bored child wants to see what will happen if they jump off the top of their shed with an umbrella. As you can guess,
ale4655 [162]

Answer:

All i kno is that that kid ain't gonna be ok

Explanation:

if u tell me how to do it ill do it

5 0
3 years ago
A parallel plate capacitor is created by placing two large square conducting plates of length and width 0.1m facing each other,
borishaifa [10]

Answer:

8.854 pF

Explanation:

side of plate = 0.1 m ,

d = 1 cm = 0.01 m,

V = 5 kV = 5000 V

V' = 1 kV = 1000 V

Let K be the dielectric constant.

So, V' = V / K

K = V / V' = 5000 / 1000 = 5

C = ε0 A / d = 8.854 x 10^-12 x 0.1 x 0.1 / 0.01 = 8.854 x 10^-12 F

C = 8.854 pF

5 0
3 years ago
Which is NOT one of the four principals of Dalton’s atomic theory?
Gre4nikov [31]

Answer:

Your answer would be letter <em><u>B</u></em><em><u>.</u></em><em><u> </u></em><em><u>Electrons</u></em><em><u> </u></em><em><u>orbit</u></em><em><u> </u></em><em><u>the</u></em><em><u> </u></em><em><u>nucleus</u></em><em><u> </u></em><em><u>in</u></em><em><u> </u></em><em><u>energy</u></em><em><u> </u></em><em><u>level</u></em><em><u>.</u></em>

Explanation:

Hope it helps..

Just correct me if I'm wrong, okay?

But ur welcome!!

(;ŏ﹏ŏ)(◕ᴗ◕✿)

8 0
3 years ago
Read 2 more answers
What is the name of the ratio of the voltage applied to a circuit and the current in a circuit
malfutka [58]
Resistance is the name of the ratio of the voltage applied to a circuit and the current in a circuit. Goes under <span>Ohm's Law</span>
4 0
3 years ago
A 100kg crate slides along a floor with a starting velocity of 21ms If the force due to friction is 8N how long will it take for
GaryK [48]

A 100kg crate slides along a floor with a starting velocity of 21 m/s. If the force due to friction is 8N, then, it will take 262.5 s for the box to come to rest.

We'll begin by calculating the declaration of the box. This can be obtained as follow:

Force (F) = –8 N (opposition)

Mass (m) = 100 Kg

<h3>Deceleration (a) =? </h3>

<h3>F = ma</h3>

–8 = 100 × a

Divide both side by 1000

a = \frac{-8}{100}

<h3>a = –0.08 ms¯²</h3>

Therefore, the deceleration of the box is –0.08 ms¯²

Finally, we shall determine the time taken for the box to come to rest. This can be obtained as follow:

Deceleration (a) = –0.08 ms¯²

Initial velocity (u) = 21 ms¯¹

Final velocity (v) = 0 ms¯¹

<h3>Time (t) =.? </h3>

<h3>v = u + at</h3>

0 = 21 + (–0.08×t)

0 = 21 – 0.08t

Collect like terms

0 – 21 = –0.08t

–21 = –0.08t

Divide both side by –0.08

t = \frac{-21}{-0.08}\\\\

<h3>t = 262.5 s</h3>

Therefore, it will take 262.5 s for the box to come to rest.

Learn more: brainly.com/question/14446351

7 0
2 years ago
Other questions:
  • Eq-45 what type of boat requires navigation lights?
    11·1 answer
  • Which of the following is a disadvantage of radio?
    11·1 answer
  • If an object's kinetic energy is zero, what is its momentum?
    13·1 answer
  • A solenoid that is 66.1 cm long has a cross-sectional area of 13.8 cm2. There are 1410 turns of wire carrying a current of 8.01
    6·1 answer
  • The space shuttle orbits 340km above the surface of the earth.What is the gravitational force on a 9.0kg sphere inside the space
    14·1 answer
  • What is a middle c site
    9·1 answer
  • URGENT
    14·1 answer
  • An athletes heart beats 62 times per minute. What is the frequency of her heart beat?
    8·1 answer
  • 1) Do liquids and gases also exert pressure?​
    15·2 answers
  • Which of the following quantities is inversely proportional to the gravitational pull between two objects?
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!