Pacific Gas and Electric Safe Tree: The right tree in the right place.
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Trees and Powerlines
Trees Are Awesome
Electricity Can Hurt
Electricity Basics
Safe Tree Safety Tips
Find the Hidden Dangers
Student Certificate
 

SafeTreeKids Website Teacher's Guide

The SafeTreeKids website uses information and activities to teach students the value of trees and the dangers of climbing, planting, or trimming trees near electric power lines. The site is geared for 4th grade use; however, it can accommodate a range of interests and reading levels. (Nonreaders will be able to play the games with adult assistance.)

Part I of this Teacher's Guide describes the contents of each section of the website. Part II contains questions and activities teachers can use to focus students' attention on key safety messages.

I. SITE OVERVIEW

Trees and Power Lines
How trees near power lines can cause electrical outages, fires, and shock.

Trees Are Awesome
What trees do for us. The parts of a tree and their functions. Dendochronology: the study of tree rings (includes a tree-ring mapping activity). Safe tree trimming.

Electricity Can Hurt
How the human body can conduct electricity; what electric shock does.

Electricity Basics
How electricity is made and how it travels through the power line distribution system. Energy-saving tips for students and their families.

SafeTree Safety Tips
Top 10 tree/power line safety tips, plus a checklist that students can use with family or friends who plant a tree.

Find the Hidden Dangers Game
Students use the safety principles they have learned and put them into practice to identify tree/power line hazards in a busy neighborhood scene.

Safety Certificate
Summary of 5 key tree/power line safety facts that students should understand when they come away from this website. Certificate has space for adult signature to encourage parent and teacher involvement.

Glossary
Definitions of unfamiliar words found on the site.

Links to Related Sites
Hot links to related websites about trees, the science of electricity, and electrical safety games.

II. QUESTIONS AND ACTIVITIES

These 20 questions review the key safety principles from the SafeTreeKids site. Here are a few ideas for how to use them with your class:

• Use as discussion points to verbally review basic electrical safety information with the whole group.

• Use as a pre- and post-test to assess student understanding of tree/power line safety principles before and after visiting the site. (To use as a written test for older students, cut and paste the questions into your word processing program, delete the answers, and print out one sheet for each student.)

• Put students into small groups and assign each group several questions; ask them to use the website to find the answers.

• After all students have completed all sections of the website, organize the class like a game show: "contestants" can continue to answer questions until they get one incorrect, at which point a new contestant takes their place.

Basic Electrical Safety Questions

1. What does electricity travel on to get from the power plant to people's houses? (Overhead and underground power lines.)

2. Which wires on power poles are the high-voltage ones? (The high-voltage lines are at the very tops of the poles.)

3. Is it okay to contact the power lines that are low on the pole, or the service drop wires that carry electricity from power poles to buildings, and that look insulated? (No, all lines and equipment on power poles are dangerous to contact. Some lines may appear to be insulated, but it's just weatherproofing.)

4. What other equipment is involved in getting electricity to where it can be used by people? (Some or all of the following are correct: substations, pole-mounted and pad-mounted transformers, service drops, meter boxes, electrical wiring, appliance cords.)

5. What are two good conductors of electricity? (Metal, water.)

6. Is the human body a good conductor of electricity? Are trees good conductors for electricity? Why/why not? (Yes for both, because they both contain a lot of water and water conducts electricity.)

7. What will happen if electricity travels through you? (You will be shocked and could be badly hurt or even killed.)

8. Do you have to be touching the ground directly to conduct electricity? (No, you could be touching something that is touching the ground, like a ladder or a tree.)

9. If a person is shocked, what can happen? (Muscle spasms, weakness, shallow breathing, rapid heartbeat, unconsciousness, or death.)

10. Why can birds sit on power lines without being shocked? (The birds do not touch the ground or anything in contact with the ground, so electricity stays in the line and does not pass through them.)

11. Can fallen power lines hurt you even if they are not sparking or humming? (Yes! That's why you should stay away from them and tell an adult right away.)

Tree/Power Line Safety Questions

12. How can trees near power lines cause electrical outages? (If a tree branch contacts a power line, safety devices shut off electricity to the line. Then electricity goes off in buildings served by the power line.)

13. How can trees near power lines cause fires? (If a tree branch touches a high-voltage power line, the electricity can heat up the branch so much that it catches fire.)

14. How can trees near power lines cause shock hazards? (Trees are great conductors for electricity. So if a tree branch touches a power line, electricity will go through the tree to the ground, and anyone who touches the tree could be hurt or killed by electric shock. Or, someone could climb a tree near a power line and actually touch the line, which would also result in serious shock.)

15. What would happen if a tree branch were to knock a power line to the ground? (It would energize the area around it with a lot of electricity and people touching the line or coming near it would be hurt or killed. It could also cause an outage and/or a fire.)

16. Why should untrained people NOT trim trees near power lines? (It's just too dangerous. They could contact the line by mistake and be hurt or killed.)

17. Who should trim trees near power lines? (Only professional tree trimmers who are certified to work near power lines.)

18. What should your parents do if they see a tree growing close to a power line? (Call Pacific Gas and Electric Company at 1-800-PGE-5000.)

19. When is it okay to play in a tree growing next to a power line? (Never! Trees near power lines are very dangerous to climb or play in.)

20. Why is it important to call 1-800-227-2600 before planting a tree? (So you can make sure you won't contact underground power lines or other buried utilities when you dig.)