Question

rite the code for a class named Funnel. A funnel is a cone-shaped object that
is used to pour liquids into small openings. For the purpose of this question,
you may assume that a Funnel is an inverted cone (see image at left) and has
a flap (a lid) at the bottom that can be opened and closed.





A Funnel has the following PUBLIC features:
a) A Funnel created without any data has a radius of 12, a height of 20,
   units measured in "millilitres", and  .

b) Alternatively, a Funnel can be created by accepting 2 whole numbers 
   representing the radius and height, and has units in "ounces" .
   
   All Funnels start out in a closed position and are empty (i.e. have a volume of
   0.00).The formula for calculating the volume of a cone is: V = 1/3 * Pi * R^2 * H
   where V = Volume, Pi = 3.14159, R^2 = radius squared, and H = height ($0.00)

c) A Funnel contains a function changeFlap( ) that opens a closed flap and
   closes an open flap and returns nothing (1 mark).

d) A Funnel also contains a function pour(int seconds) that empties the
   Funnel according to the formula: f = 2.5/R per second
   (where f = amount poured, R = radius), but ONLY FOR Funnel's that have
   OPEN FLAPS!
   The function also displays the amount poured for each second, and
   finally returns the total amount poured.
   So, for a default Funnel with a volume of 3015.9264, the function pour(2)
   would display:
   after 1 secs, poured 0.0075 millilitres, volume now at 3015.9189
   after 2 secs, poured 0.0075 millilitres, volume now at 3015.9114
   The function would return 0.015 for THIS EXAMPLE ONLY!

   If the Funnel's flap is closed, then only the line:
   "Sorry Funnel flap is closed!"
   is displayed, and 0.00 would be returned.

   This function permanently reduces the Funnel's volume .

e) A Funnel contains another function pour( ) that computes and returns the
   exact number of seconds (including fractional portions) required to
   completely empty the Funnel .


f) The postfix ++ operator increases the Funnel's radius by 1
   and returns the Funnel's new volume .

g) The prefix ++ operator increases the Funnel's height by 1
   and returns the Funnel's new volume .

h) A function called calcVolume( ) that computes and returns the
   Funnel's volume .

i) A function called getVolume( ) that computes and returns the
   Funnel's current volume .

For example, the following program:

int main( ) {
   Funnel f1, f2(6, 15);
   float amount, volumeF1, volumeF2, seconds;

   volumeF1 = f1++; // sets Funnel f1's radius to 13
   volumeF2 = ++f2; // sets Funnel f2's height to 16

   cout << "f1's volume is: " << volumeF1 << endl;
   cout << "f2's volume is: " << volumeF2 << endl;

   amount = f1.pour(5); // flap is closed, so does not pour anything
   f1.changeFlap( );

   amount = f1.pour(5);

   cout << "amount poured from Funnel f1: " << amount << endl;

   cout << "------------------------------------------------" << endl;

   seconds = f2.pour( );
   cout << "it takes " << seconds << " seconds to empty Funnel f2" << endl;

   f2.changeFlap( );
   f2.pour(3);

   cout << "f1's volume is: " << f1.getVolume( ) << endl;
   cout << "f2's volume is: " << f2.getVolume( ) << endl;

   return 0;
}

would display:
f1's volume is: 3539.52
f2's volume is: 603.185
Sorry Funnel flap is closed!
after 1 secs, poured 0.192308 millilitres, volume now at 3539.33
after 2 secs, poured 0.192308 millilitres, volume now at 3539.14
after 3 secs, poured 0.192308 millilitres, volume now at 3538.95
after 4 secs, poured 0.192308 millilitres, volume now at 3538.76
after 5 secs, poured 0.192308 millilitres, volume now at 3538.56
amount poured from Funnel f1: 0.961538
------------------------------------------------
it takes 1447.64 seconds to empty Funnel f2
after 1 secs, poured 0.416667 ounces, volume now at 602.769
after 2 secs, poured 0.416667 ounces, volume now at 602.352
after 3 secs, poured 0.416667 ounces, volume now at 601.935
f1's volume is: 3538.56
f2's volume is: 601.935

Answer 1

#include <iostream>
using namespace std;
int flap=0;
class Funnel {
   public:
          Funnel(){                     //default constructor
             radius=12;
         height=20;
         volume= ((3.14*radius*radius*height)/3)/29.5735;   //unit in millilitres
      }
      Funnel(int rad, int hght){    //parametrized constructor
         radius=rad;
         height=hght;
         volume= (3.14*radius*radius*height)/3;   //unit in ounces
      }
    //function to open and close flap
      void changeFlap(){
         if(flap==0)
            flap=1;
         else
            flap=0;
      }
//calculates the volume after every second, the liquid is poured out
      float pour(int seconds){
         float f= 0.00;
            int i=1;
         if(flap==0){
            cout<<"Sorry, Flap is closed!";
            return f;
         }
         else {
            while(i <= seconds){
              f= (2.5/ radius)/29.5735;
              volume= volume-f;
              cout<<"after "<<i<<" seconds, poured"<<f<<" millilitres, volume now at"<<volume;
              return (f*seconds);
         }   
      }
 //calculates the time required to empty the funnel
    float pour(){
      float time;
      time= (radius * volume) /2.5;
      return time;
    }
      // Overload postfix ++ operator 
    friend Funnel operator++(Funnel &ob)
    {   
        ob.radius++;
        return ( (3.14*radius*radius*height)/3);
    }
      // Overload postfix ++ operator 
    friend Funnel operator++(Funnel &ob, int h)
    {
        ++ob.height;
        return ( (3.14*radius*radius*height)/3);
    }
     //calculates the volume
     float calcVolume(){
         return ( (3.14*radius*radius*height)/3);
    }
    //returns the current volume
    float getVolume(){
         return volume;
    }
       
   private:
      int radius;      // radius of the funnel
      int height;      // Height of the funnel
      float volume;   // volume of the funnel
};