Question

in java

Implement a class Balloon. A balloon starts out with radius 0. Supply a method

public void inflate(double amount)

that increases the radius by the given amount. Supply a method

public double getVolume()

that returns the current volume of the balloon; volume of a balloon is represented as:

V = (4/3) * PI * r^3

Use Math.PI for the value of π. To compute the cube of a value r, you can use Math.pow (https://www.tutorialspoint.com/java/lang/math_pow.htm) or r*r*r

Write a tester program that inflates the balloon to 10, print the volume, then inflate it to 15 and print the volume.

Radius: 10, volume: 4188.79

Radius: 15, volume: 14137.17

Answer 1

//Balloon.java
public class Balloon {
    private double radius;

    public Balloon() {
        radius = 0;
    }

    public void inflate(double amount){
        radius += amount;
    }

    public double getVolume(){
        return (4.0/3)*Math.PI*Math.pow(radius,3);
    }

    public static void main(String[] args) {
        Balloon balloon1 = new Balloon();
        balloon1.inflate(10);
        System.out.printf("Volume = %.2f\n",balloon1.getVolume());

        Balloon balloon2 = new Balloon();
        balloon2.inflate(15);
        System.out.printf("Volume = %.2f\n",balloon2.getVolume());
    }
}

Volume = 4188.79
Volume = 14137.17