Paper Writing Services these lines: final double for PI, since it is a floating point constant; int for radius, since it is an integer variable,

Abstract
that variable each time you compute it. Add two additional print statements to print your results. Be sure your results are clearly labeled. 2. When the radius of a circle doubles, what happens to its circumference and area? Do they double as well? You can determine ts by dividing the second area by the first area. Unfortunately, as

Area and Circumference of a Circle Study the program below, wch uses both variables and constants: // ************************************************************ //  Circle.java // //  Print the area of a circle with two different radii // ************************************************************ public class Circle { public static void main(String[] args) { final double PI = 3.14159; int radius = 10; double area = PI * radius * radius; System.out.println(“The area of a circle with radius ” + radius + ” is ” + area); radius = 2 0; area = PI * radius * radius; System.out.println(“The area of a circle with radius ” + radius + ” is ” + area); } } Some tngs to notice: The first three lines inside main are declarations for PI, radius, and area. Note that the type for each is given in these lines: final double for PI, since it is a floating point constant; int for radius, since it is an integer variable, and double for area, since it will hold the product of the radius and PI, resulting in a floating point value. These first three lines also hold initializations for PI, radius, and area. These could have been done separately, but it is often convenient to assign an initial value when a variable is declared. The next line is simply a print statement that shows the area for a circle of a given radius. The next line is an assignment statement, giving variable radius the value 20. Note that ts is not a declaration, so the int that was in the previous radius line does not appear here. The same memory location that used to hold the value 10 now holds the value 20—we are not setting up a new memory location. Similar for the next line—no double because area was already declared. The final print statement prints the newly computed area of the circle with the new radius. Save ts program, wch is in file Circle.java, into your directory and modify it as follows: 1. The circumference of a circle is two times the product of Pi and the radius. Add statements to ts program so that it computes the circumference in addition to the area for both circles. You will need to do the following: Declare a new variable to store the circumference. Store the circumference in that variable each time you compute it. Add two additional print statements to print your results. Be sure your results are clearly labeled. 2. When the radius of a circle doubles, what happens to its circumference and area? Do they double as well? You can determine ts by dividing the second area by the first area. Unfortunately, as it is now the program overwrites the first Chapter 2: Data and Expressions 16 area with the second area (same for the circumference). You need to save the first area and circumference you compute instead of overwriting them with the second set of computations. So you’ll need two area variables and two circumference variables, wch means they’ll have to have different names (e.g., area1 and area2). Remember that each variable will have to be declared. Modify the program as follows: Change the names of the area and circumference variables so that they are different in the first and second calculations. Be sure that you print out whatever you just computed. At the end of the program, compute the area change by dividing the second area by the first area. Ts gives you the factor by wch the area grew. Store ts value in an appropriately named variable (wch you will have to declare). Add a println statement to print the change in area that you just computed. Now repeat the last two steps for the circumference. Look at the results. Is ts what you expected? 3. In the program above, you showed what happened to the circumference and area of a circle when the radius went from 10 to 20. Does the same tng happen whenever the radius doubles, or were those answers just for those particular values? To figure ts out, you can write a program that reads in values for the radius from the user instead of having it written into the program (“hardcoded”). Modify your program as follows: At the very top of the file, add the line import java.util.Scanner; Ts tells the compiler that you will be using methods from the Scanner class. In the main method create a Scanner object called scan to read from System.in. Instead of initializing the radius in the declaration, just declare it without giving it a value. Now add two statements to read in the radius from the user: A prompt, that is, a print statement that tells the user what they are supposed to do (e.g., “Please enter a value for the radius.”); A read statement that actually reads in the value. Since we are assuming that the radius is an integer, ts will use the nextInt() method of the Scanner class. When the radius gets it second value, make it be twice the original value. Compile and run your program. Does your result from above hold? Chapter 2: Data and Expressions 17

Sample references
  • (‘Costanza, R., W. J. Mitsch, and J. W. Day. 2006. A new vision for New Orleans and the Mississippi delta: Applying ecological economics and ecological engineering. Frontiers in Ecology and the Environment 4(9):465-472.’,)
  • (‘Carey, I. M., Shah, S. M., Harris, T., DeWilde, S., & Cook, D. G. (2013). A new simpleprimary care morbidity score predicted mortality and better explains betweenpractice variations than the Charlson Index. Journal of Clinical Epidemiology,66(4), 436-444.’,)
  • (‘Rousseau, DM. 2006. Is there such a thing as evidence-based management? Acad. Mgt. Rev. 31: 256-69 ‘,)
  • (‘Sonnentag, S. 1998. Expertise in professional software design: a process study. J. App. Psych. 83: 703-715’,)

Need your ASSIGNMENT done? Use our paper writing service to score better and meet your deadline.


Click Here to Make an Order Click Here to Hire a Writer