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
13

A stainless steel ball (=8055 kg/m3, Cp= 480 J/kgK) of diameter D =15 cm is removed from theoven at a uniform temperature of 3

50oC. The ball is then subjectedto the flow of air at 1 atm pressure and 30oC with a velocityof 6 m/s. The surface temperature of the ball eventuallydrops to 250oC. Determine the average convection heat transfercoefficient during this cooling process and estimate howlong this process has taken.
Engineering
1 answer:
aleksandrvk [35]3 years ago
3 0

Answer:

i) 25.04 W/m^2 .k

ii) 23.82 minutes = 1429.2 secs

Explanation:

Given data:

Diameter of steel ball = 15 cm

uniform temperature = 350°C

p = 8055 kg/m^3

Cp = 480 J/kg.k

surface temp of ball drops to  250°C

average surface temperature = ( 350 + 250 ) / 2 = 300°C

<u>i) Determine the average convection heat transfer coefficient during the cooling process</u>

<em>Note : Obtain the properties of air at 1 atm at average film temp of 30°C from the table  " properties of air "  contained in your textbook</em>

average convection heat transfer coefficient = 25.04 W/m^2 .k

<u>ii) Determine how long this process has taken </u>

Time taken by the process = 23.82 minutes = 1429.2 seconds

Δt = Qtotal / Qavg = 683232 / 477.92 = 1429.59 secs

attached below is the detailed solution of the given question

You might be interested in
3. (5%) you would like to physically separate different materials in a scrap recycling plant. describe at least one method that
Likurg_2 [28]

One of the methods that are used to separate polymers, aluminium alloys, and steels from one another is the Gravitation Separation method.

One straightforward technique is to run the mixture through a magnet, which will keep the steel particles on the magnet and separate them from the polymer.

What is the Gravitation Separation method?

When it is practicable to separate two components using gravity, i.e., when the combination's constituent parts have different specific weights, gravity separation is a technique used in industry. The components can be in suspension or in a dry granular mixture.

Polymers, Steel and Aluminium alloys can be readily split apart. The technique depends on how the two components are combined. The approach used is gravitational density. Due to the significant difference in relative specific mass values between steel and polymers (which range from 1.0 to 1.5), it is possible to separate them using flotation in a liquid that is safe and has the right density.

Therefore, the Gravitation Separation method is used to separate polymers, aluminium alloys and steels.

To learn more about the Polymer from the given link

brainly.com/question/2494725

#SPJ4

8 0
1 year ago
Question 8(Multiple Choice Worth 2 points)
8090 [49]

Answer:

4 number answer is correct.

8 0
2 years ago
To put out a class D metal fire, you must _______ the fire.
gladu [14]

To put out a class D metal fire, you must smother the fire and eliminate the oxygen element in the fire.

<h3>What is a Class D fire?</h3>

A class D fire is a type of fire that cannot be extinguished by water. This is because adding water to it reacts with other elements in the fire intensifying the fire even more.

Smothering in this context involves adding a solution like carbon dioxide (CO2) into the fire, this results in a reduction of oxygen in the atmosphere surrounding the class D fire.

By so doing, smothering the fire eliminates the oxygen element in the fire, thereby extinguishing the fire.

You can learn more about extinguishing fires here https://brainly.in/question/760550

#SPJ1

7 0
2 years ago
Primary Creep: slope (creep rate) decreases with time
Igoryamba

Answer:

true

Explanation:

Creep is known as the time dependent deformation of structure due to constant load acting on the body.

Creep is generally seen at high temperature.

Due to creep the length of the structure increases which is not fit for serviceability purpose.

When time passes structure gain strength as the structure strength increases with time so creep tends to decrease.

When we talk about Creep rate for new structure the creep will be more than the old structure i.e. the creep rate decreases with time.

5 0
3 years ago
A 1 turn coil carries has a radius of 9.8 cm and a magnetic moment of 6.2 X 10 -2 Am 2. What is the current through the coil?
Alexus [3.1K]

Answer:

The current through the coil is 2.05 A

Explanation:

Given;

number of turns of the coil, N = 1

radius of the coil, r = 9.8 cm = 0.098 m

magnetic moment of the coil, P = 6.2 x 10⁻² A m²

The magnetic moment is given by;

P = IA

Where;

I is the current through the coil

A is area of the coil = πr² = π(0.098)² = 0.03018 m²

The current through the coil is given by;

I = P / A

I = (6.2 x 10⁻² ) / (0.03018)

I = 2.05 A

Therefore, the current through the coil is 2.05 A

6 0
3 years ago
Other questions:
  • Hi, I have an assignment in which i needs to write a report on (Rationalization of electrical energy consumption) and i need cha
    6·1 answer
  • If d=0.25m and D=0.40m. Assume headloss from the contraction to the end of the pipe can be found as hų = 0.9 (V is velocity in t
    8·1 answer
  • If a machine uses LESS effort to overcome a given resistance force (if Fe is less than FR), it has an actual mechanical advantag
    13·1 answer
  • A diesel engine with an engine volume of 4.0 L and an engine speed of 2500 rpm operates on an air–fuel ratio of 18 kg air/kg fue
    6·2 answers
  • Create a Python program that will produce the following output:
    7·1 answer
  • Please please help please with this this is the link for the story PLEASE PLEASE HELP PLEASE PLEASE help please
    7·1 answer
  • What are the major types of stone used in construction? How do their properties differ? What sequence of operations would be use
    10·1 answer
  • A golfer and her caddy see lightning nearby. the golfer is about to take his shot with a metal club, while her caddy is holding
    12·1 answer
  • What Is Photosynthesis ?​
    7·2 answers
  • Write a program that takes three numbers as input from the user, and prints the largest.
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!