The speed of sound depends on the material the sound is passing through. Below is the approximate speed of sound (in feet per second) for air, water and steel:

air: 1,100 feet per second

water: 4,900 feet per second

steel: 16,400 feet per second

Write a program that displays a menu allowing the user to select air, water, or steel. After the user has made a selection, he or she should be asked to enter the distance a sound wave will travel in the selected medium. The program will then display the amount of time it will take.

Menu. The menu should look exactly like this:

Select a medium:
1. Air
2. Water
3. Steel

The Java Program for the given problem is as below. Directly copy the code and run it on your machine.

Explanation:

Refer the Screenshots attached for the output.

import java.io.BufferedReader;

import java.io.InputStreamReader;

public class TheSpeedOfSound {

public static void main(String[] s)

{

String medium;

double distance;

double time;

try{

BufferedReader choice = new BufferedReader(new InputStreamReader(System.in));

System.out.println("Enter one of the following: air, water, or steel: ");

medium = choice.readLine(); // reading input i.e. air, water or steel

//check for air water and steel

if (medium.equalsIgnoreCase("air") || medium.equalsIgnoreCase("water") || medium.equalsIgnoreCase("steel")){

System.out.println("Enter the distance the sound wave will travel: ");

distance = Double.parseDouble(choice.readLine()); // read distance value if it is air water or steel

switch (medium)

{

//if medium is air

case "air":

time = distance/1100;

System.out.print("It will take " + time + " seconds.");

break;

//if medium is water

case "water":

time = distance/4900;

System.out.print("It will take " + time + " seconds.");

break;

//if medium is steel

case "steel":

time = distance/16400;

System.out.print("It will take " + time + " seconds.");

break;

}

}

else{

System.out.print("Sorry, you must enter air, water, or steel.");  

}

}

catch(Exception e){

e.printStackTrace();

}

}

}

answer: when the substance contain the two parts (polar and non-polar) like soap.

explanation:

soap is produced from the basic hydrolysis of ester "saponification", it is considered as a salt of hydrocarbons. the soap molecule contains the two parts: a polar group   (-coo-na+) and a non-polar group (r-hydrocarbon part). the polar group is called the head and the tail is the non-polar group. the polar group is hydrophilic in nature (water loving) and the non-polar group is hydrophobic in nature (water repelling).the polar/non-polar nature of a substance is useful that it can dissolve the non-polar substances by the polar part and also can dissolve the polar substances by the non-polar part. it commonly used in detergents and soaps.

Ithink your answer is b