ELECTRICITY AND SAFETY

Introduction

We use electricity in many ways every day. Most of the appliances and other electrical equipment found in many homes are designed for safety. However, manufacturers cannot guarantee that users will not be careless or that accidents will not happen. You must be careful around electricity because your life may depend on it.

How does electricity cause injury? As you may have learned in your science class, your brain sends instructions to the other parts of your body by means of electrical and chemical signals. An electric shock disrupts those signals. If the current enters the heart or respiratory system, your heart can stop beating and your lungs can fail to take in oxygen, causing suffocation. Other muscles may also be paralyzed. If the shock comes from a power tool, for example, the person may be unable to let go.

How much electricity is needed to kill? That is not easy to determine, because many factors are involved. Although the human body is a conductor, it does offer some resistance. How much resistance depends on the path the electricity takes, the person’s general health, whether the person’s skin is wet or dry, and the length of time the person is exposed. However, a human being can die from as little as one-tenth the amount of electricity required to light a ten-watt light bulb.

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Task

For this WebQuest, your job is to investigate the dangers of electricity and how to use it safely. To demonstrate what you have learned, you will answer the questions included here. You will also complete one of the activities described at the end of this WebQuest.

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Process

Read through the following questions. Then research the Internet resources that are provided for you. As you explore the sites, look for answers to the questions. Keep a record of any sites where you find answers by noting the title and URL (Internet address). For example:

            (title) Technology Student Association
            (URL) http://www.tsaweb.org

1. You have learned the differences between current, voltage, and resistance. In cases of electric shock, which of these three is most responsible for the level of injury? How is it measured?
   
   
2. Why do human beings make good conductors of electricity?
   
   
3. Suppose you observe someone receive a severe electric shock. List at least three things that should be done immediately.
   
   
4. What does a ground fault circuit interrupter do?
   
   
5. How many home fires are caused each year in the U.S. by misuse of electric cords and plugs?
   
   
6. Suppose you discover an electrical fire in your home List at least three things you should do.



7. How does a circuit breaker work to protect against fires?
   
   

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Resources

Visit the Web sites listed here to find information that will enable you to answer the questions. You may use additional sites if you wish. Be sure to keep a record of any sites you use.

• How Electricity Works provides basic information from its origins in the atom to how it is generated.

• How Circuit Breakers Work discusses their operation.

• Be Prepared in an Electrical Emergency gives tips for safety.

• Electrical Safety World lists steps to take in an emergency.

• Be Safe Around Electricity discusses how injuries occur.

• Electrical Safety: GFCI explains how they work for safety.

• Facts and Figures provides interesting statistics about electrical safety.

• Electrical Safety includes steps to take in case of fire.

• An Electric Circuit provides information about different types of circuits, as well as a general tutorial on electricity.

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Activities

Several activities are described below. Complete one of these activities (your choice) to demonstrate understandings you’ve gained by going on this WebQuest.

• Interview the school nurse or another medical professional to learn about how CPR (cardio-pulmonary resuscitation) works and why it might be required in cases of severe electric shock. Share your findings with the class.
• Create a poster or model explaining how a circuit breaker works.
• Select an electrical power tool and give a presentation to the class on its safe operation and maintenance, paying particular attention to the cord, power supply, plug, and other factors having to do with electricity.
• Create a word puzzle, such as a crossword or word search, based on terms having to do with electricity, such as circuit, ampere, watt, and so on.

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