Throughout the book we’ve included Making a Difference exercises in which you’ll be asked to work on problems that really matter to individuals, communities, countries and the world.

1. 1.8 (Test Drive: Carbon Footprint Calculator) Some scientists believe that carbon emissions, especially from the burning of fossil fuels, contribute significantly to global warming and that this can be combatted if individuals take steps to limit their use of carbon-based fuels. Various organizations and individuals are increasingly concerned about their “carbon footprints.” Websites such as TerraPass

   
   http://www.terrapass.com/carbon-footprint-calculator-2/
   

   and Carbon Footprint

   
   http://www.carbonfootprint.com/calculator.aspx
   

   provide carbon footprint calculators. Test drive these calculators to determine your carbon footprint. Exercises in later chapters will ask you to program your own carbon footprint calculator. To prepare for this, research the formulas for calculating carbon footprints.

2. 1.9 (Test Drive: Body Mass Index Calculator) By recent estimates, two-thirds of the people in the United States are overweight and about half of those are obese. This causes significant increases in illnesses such as diabetes and heart disease. To determine whether a person is overweight or obese, you can use a measure called the body mass index (BMI). The United States Department of Health and Human Services provides a BMI calculator at http://www.nhlbi.nih.gov/guidelines/obesity/BMI/bmicalc.htm. Use it to calculate your own BMI. An exercise in Chapter 2 will ask you to program your own BMI calculator. To prepare for this, research the formulas for calculating BMI.

3. 1.10 (Attributes of Hybrid Vehicles) In this chapter you learned the basics of classes. Now you’ll begin “fleshing out” aspects of a class called “Hybrid Vehicle.” Hybrid vehicles are becoming increasingly popular, because they often get much better mileage than purely gasoline-powered vehicles. Browse the web and study the features of four or five of today’s popular hybrid cars, then list as many of their hybrid-related attributes as you can. For example, common attributes include city-miles-per-gallon and highway-miles-per-gallon. Also list the attributes of the batteries (type, weight, etc.).

4. 1.11 (Gender Neutrality) Some people want to eliminate sexism in all forms of communication. You’ve been asked to create a program that can process a paragraph of text and replace gender-specific words with gender-neutral ones. Assuming that you’ve been given a list of gender-specific words and their gender-neutral replacements (e.g., replace “wife” with “spouse,” “man” with “person,” “daughter” with “child” and so on), explain the procedure you’d use to read through a paragraph of text and manually perform these replacements. How might your procedure generate a strange term like “woperchild,” which is actually listed in the Urban Dictionary (www.urbandictionary.com)? In Chapter 4, you’ll learn that a more formal term for “procedure” is “algorithm,” and that an algorithm specifies the steps to be performed and the order in which to perform them.

5. 1.12 (Privacy) Some online e-mail services save all e-mail correspondence for some period of time. Suppose a disgruntled employee of one of these online e-mail services were to post all of the e-mail correspondences for millions of people, including yours, on the Internet. Discuss the issues.

6. 1.13 (Programmer Responsibility and Liability) As a programmer in industry, you may develop software that could affect people’s health or even their lives. Suppose a software bug in one of your programs were to cause a cancer patient to receive an excessive dose during radiation therapy and that the person either was severely injured or died. Discuss the issues.

7. 1.14 (2010 “Flash Crash”) An example of the consequences of our dependency on computers was the so-called “flash crash” which occurred on May 6, 2010, when the U.S. stock market fell precipitously in a matter of minutes, wiping out trillions of dollars of investments, and then recovered within minutes. Use the Internet to investigate the causes of this crash and discuss the issues it raises.