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djyliett [7]
3 years ago
8

An inventor claims to have developed a refrigerator that at steady state requires a net power input of 1.1 horsepower to remove

12,000 Btu/h of energy by heat transfer from the freezer compartment at 0°F and discharge energy by heat transfer to a kitchen at 70°F. Evaluate this claim.
Engineering
1 answer:
Lynna [10]3 years ago
6 0

Answer:

The inventor's claim is false in the sense that no thermal machine can violate the first thermodynamic law.

Explanation:

The inventor's claim could not be possible as no thermal machine can transfer more heat than the input work consumed. If we expose the thermal efficiency:

n=Q out / W in

Where Q and W both must be in the same power unit, so we will convert the remove heat from BTU/hr to hp:

12000 BTU/hr = 4.72 hp

Therefore by comparing, we notice that the removing heat of 4.75 hp is large than the delivered work of 1.11 hp. By evaluating the efficiency:

[tex]n=4.75 hp / 1.1 hp  = 4.3 > 1[/tex]

You might be interested in
8.19 - Airline Reservations System (Project Name: Airline) - A small airline has just purchased a computer for its new automated
e-lub [12.9K]

Answer:

The App is written in C++ language using dev C++.

Explanation:

/******************************************************************************

You can run this program in any C++ compiler like dev C++ or any online C++ compiler

*******************************************************************************/

#include <iostream>

using namespace std;

class bookingSeat// class for airline reservation system

{

  private:

   

   

  bool reserveSeat[10];// 10 seats (1-5) for first class and 6-10 for economy class

  int firstClassCounter=0;//count first class seat

  int economyClassCounter=5;//count economy class seat

  char seatPlacement;/* switch between economy and first clas seat----- a variable for making decision based on user input*/

  public:  

  void setFirstClassSeat()//

  {

      if(firstClassCounter<5)// first class seat should be in range of 1 to 5

      {

          reserveSeat[firstClassCounter]=1; /*set first class seat..... change index value to 1 meaning that it now it is reserved*/

          cout<<"Your First Class seat is booked and your seat no is "<<firstClassCounter+1; //display seat number reserved

          firstClassCounter++; //increament counter

      }

      else//in case seats are ful

      {

          cout<<"\nSeats are full";

          if(economyClassCounter==10 && firstClassCounter==5)

          {

              cout<<"\n Next flight leaves in 3 hours.";

          }

          else

          {

              cout<<"\nIt’s acceptable to be placed to you in the first-class section  y/n ";//take input from user

              cin>>seatPlacement;//user input

              if(seatPlacement=='y')//if customer want to reserve seat in first class

              {

                  setEconomyClassSeat();// then reserve first class seat

              }

              else

              {

                  cout<<"\n Next flight leaves in 3 hours.";

               }

               

          }

      }

       

  }

  void setEconomyClassSeat()//set economy class seat

  {

    if(economyClassCounter<10)//seat ranges between 6 and 10

      {

          reserveSeat[economyClassCounter]=1;// reserve economy class seat

          cout<<"Your Economy class seat is booked and your seat no is "<<economyClassCounter+1;//display reservation message about seat

          economyClassCounter++;//increament counter

      }

      else// if economy class seats are fulled

      {

          cout<<"\nSeats are full";

          if(economyClassCounter==10 && firstClassCounter==5)//check if all seats are booked in both classes

          {

              cout<<"\n Next flight leaves in 3 hours.";

          }

          else

          {

              cout<<"\nIt’s acceptable to be placed to you in the first-class section  y/n ";//take input from user

              cin>>seatPlacement;//user input

              if(seatPlacement=='y')//if customer want to reserve seat in first class

              {

                  setFirstClassSeat();// then reserve first class seat

              }

              else

              {

                  cout<<"\n Next flight leaves in 3 hours.";

               }

               

          }

      }

  }

   

   

};

int main()

{   int checkseat=10;// check seat

   int classType;//class type economy or first class

   bookingSeat bookseat;//object declaration of class bookingSeat

   while(checkseat<=10)//run the application until seats are fulled in both classes

   {

       cout<<"\nEnter 1 for First Class and 2 for Economy Class ";

       cin>>classType;//what user entered

       switch (classType)//decide which seat class to be reserved  

       {

           case 1://if user enter 1 then reserve first class seat

           bookseat.setFirstClassSeat();

           break;

           case 2://if user enter 2 then reserve the economy class seat

           bookseat.setEconomyClassSeat();

           

       }

       

   }

   

   return 0;

}

8 0
3 years ago
A 100 ft long steel wire has a cross-sectional area of 0.0144 in.2. When a force of 270 lb is applied to the wire, its length in
blondinia [14]

Answer:

(a) The stress on the steel wire is 19,000 Psi

(b) The strain on the steel wire is 0.00063

(c) The modulus of elasticity of the steel is 30,000,000 Psi

Explanation:

Given;

length of steel wire, L = 100 ft

cross-sectional area, A = 0.0144 in²

applied force, F = 270 lb

extension of the wire, e = 0.75 in

<u>Part (A)</u> The stress on the steel wire;

δ = F/A

   = 270 / 0.0144

δ  = 18750 lb/in² = 19,000 Psi

<u>Part (B)</u> The strain on the steel wire;

σ = e/ L

L = 100 ft = 1200 in

σ = 0.75 / 1200

σ = 0.00063

<u>Part (C)</u> The modulus of elasticity of the steel

E = δ/σ

   = 19,000 / 0.00063

E = 30,000,000 Psi

4 0
3 years ago
Type the correct answer in the box. Spell all words correctly. Mike is constructing a project in which he uses a motor. How can
tankabanditka [31]
If it is. DC, direct current reverse the polarity of power leads on the motor.

If it is a 3 phase ac alternating current, reverse any of the two of three leads.

Disconnect power before attempting.
6 0
3 years ago
Can someone tell me what car year and model this is please
Arlecino [84]

Answer:

i think 1844

Explanation:

5 0
3 years ago
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Which of these are not referenced in an assembly?
Otrada [13]
E. Parts they don’t resemble
7 0
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