I just wanted to say thanks you to Brainly. This website is a huge help!

a vertical cylindrical container is being cooled in ambient air at 25 °C with no air circulation. if the initial temperature of

Sloan [31]

Answer:

the surface heat-transfer coefficient due to natural convection during the initial cooling period. = 4.93 w/m²k

Explanation:

check attachement for answer explanation

7 0

3 years ago

Read 2 more answers

Based on the concept that it is better to prevent falls happening in the first place, which of the following safety methods meet

alekssr [168]

Answer:fall arrest harness

Explanation:cuz it’s just right

7 0

3 years ago

Suppose that we have a 1000pF parallel-plate capacitor with air dielectric charged to 1000V. The capacitor terminals are open ci

N76 [4]

Answer:

W = 1 mJ

V_new = 2000 V

W_new = 2 mJ

The extra energy came from the work done from moving the plates

Explanation:

We are given;

Capacitance; C = 1000pF = 10^(-9) F

Voltage; V = 1000V

Now,formula for stored energy in a parallel plate capacitor is given by;

W = (1/2)CV² = (1/2)(10^(-9))(1000²) = 0.5 mJ

However, in this case, it's W = 0.5 x 2 = 1 mJ since parallel-plate capacitor with air dielectric

When plates are moved and distance between plates is doubled(net charge is the same), thus we can calculate voltage from;

Q = CV

Since, C_new = C/2

Thus,

Q = (C/2)V_new

V_new = 2Q/C

Thus, V_new = 2V

Thus, V_new = 2 x 1000 = 2000 V

Now,

W_new = (1/2)C_new•(V_new)² = (1/2) (0.5C)•(2V)² = CV² = 2W = 2 x 1 = 2mJ

4 0

3 years ago

Explain how the ideal vapour compression refrigerator cycle is an improvement upon the Carnot cycle. Use any two of the problems

Grace [21]

answer explanation:

<u>Basically, the Carnot cycle is turning a heat differential into mechanical energy, then using mechanical energy to recreate the heat differential. A heat pump only turns mechanical energy into a heat differential. It exchanges the gas being compressed on an ongoing basis and does not extract mechanical energy from it, this continuous loss of mechanical energy input is what allows continuous generation of a heat differential.</u>

<u>Also, the Carnot cycle is an idealized theoretical model, not a practically achievable engineering goal. It illustrates the essential mechanism by which heat differentials can be turned into mechanical energy and vice versa, it has to ignore the fact of inefficiency in conversion between mechanical energy and heat differential for the sake of illustrating a set of ideal processes. A real refrigeration system has to deal with the question of whether the system is pumping away more heat than it generates itself through inefficiency.</u>

8 0

2 years ago

Write a program that will produce a report showing the current and max-imum enrollments for a number of classes. Your applicatio

Andru [333]

Answer:

Check the explanation

Explanation:

CODE

using System;

using System.Collections.Generic;

using System.Text;

using System.Runtime.InteropServices;

namespace listofcourses

{

class Course1

{

public string coursename;

public int courseenrol;

public int maximum;

}

class Courses1

{

public List<Course1> colist = new List<Course1>();

public int coursemaximum;

public int addRecord(string num, int err,int maximum)

{

Course1 c1 = new Course1();

c1.coursename = num;

c1.courseenrol = err;

c1.maximum=maximum;

colist.Add(c1);

coursemaximum = colist.Count;

return 1;

}

class Implement

{

static public Courses1 cos = new Courses1();

static public void printrecord()

{

Console.WriteLine("_______________________________________________________________");

Console.WriteLine("SNo Class Name currentEnroll MaximumEnroll");

Console.WriteLine("_______________________________________________________________");

for (int i = 0; i < cos.coursemaximum; i++)

{

Console.Write("{0, -5}", i + 1);

Console.Write("{0, -19}", cos.colist[i].coursename);

Console.Write("{0, -7}", cos.colist[i].courseenrol);

Console.Write("{0, -7}", cos.colist[i].maximum);

Console.WriteLine();

}

Console.WriteLine("_______________________________________________________________");

}

static public void getRecords()

{

Console.Write("please enter Course Name: ");

string num;

int c1,m1;

num = Console.ReadLine();

Console.Write("Enter current enrollment");

c1= Convert.ToInt32(Console.ReadLine());

Console.Write("Enter maximum enrollment");

m1= Convert.ToInt32(Console.ReadLine());

cos.addRecord(num,c1,m1);

}

static void Main(string[] args)

{

Console.WriteLine("Course Enrollment");

Console.Write("please Enter the number of courses: ");

int ncval = -1;

string xval = Console.ReadLine();

ncval= Convert.ToInt32(xval);

for (int i = 1; i <= ncval; i++)

{

Console.WriteLine("\nEnter " + i.ToString() + " course enrollment\n");

getRecords();

}

printrecord();

char k1 = Console.ReadKey().KeyChar;

}

Kindly check the code output below.

3 0

3 years ago