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Magnets and Compass Unit

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Activity 1: Properties of Bar Magnets	Activity 2: Building a Compass

Table of Contents:

1. Overview
2. Introduction
3. Activity 1: Properties of Magnets
   • Materials
   • Step by Step Instructions
   • Sample Student Worksheet
4. Activity 2: Building a Compass
   • Tools
   • Materials
   • Step by Step Instructions
5. Assessment
   • During the Lesson
   • At the End of the Lesson
6. Suggestions for expanding this activity
7. Resources
8. Learning Standards
   • Illinois Early Elementary Learning Standards in Science, Math, and English/Language Arts
   • Illinois Late Elementary Learning Standards in Science, Math, and English/Language Arts
   • National Science Education Standards

Overview

During these hands-on, minds-on activities, students will be asked to explore magnets and to build a compass using magnetism. These activities demonstrate the properites of bar magnets, how to magnetize a metal object, how to build a compass, and how to operate this compass.

The activities are simple and inexpensive, yet they provide endless possiblities for expanding lesson plans and meeting learning standards. The minimum amount of time needed for this lesson is 90 minutes.

Introduction

The introduction to this lesson could include a discussion about the concept of magnetism (i.e. the properties and applications of magnets). It could also include an introduction to using a compass. Here are some sample discusion questions:

• What is magnetism?
• What kind of objects are magnets attracted to?
• Why do you think magnets "stick" to these objects?
• What is a compass?
• How is a compass used?

Activity 1: Properties of Magnets

Materials

For the Properties of Bar Magnets Activity you will need 2 bar magnets for each pair of students.

Note: If you feel your students might be unfamiliar with the tools and materials, you should review the tools and materials vocabulary with them before performing the activity.

Steps

Step 1: Touching Two Magnets at the Same Poles

On a desk or smooth surface, bring the south pole of bar magnet #1 near the south pole of bar magnet #2.

Now bring the north pole of magnet #1 near the north pole of magnet #2. . Record your results in the sample worksheet, if desired.

Step 2: Touching Two Magnets at Opposite Poles

On the same surface, bring the south pole of bar magnet #1 to the north pole of bar magnet #2.

Now bring the north pole of bar magnet #1 to the south pole of bar magnet #2. Record what happens in the sample worksheet, if desired.

Worksheets

Directions: Use two bar magnets that are the same size.

1. Try to touch the two south poles together. What happened to the magnets? Do they push each other away from each other or do they pull each other together?
2. Try to touch the two north poles together. What happened to the magnets? Do they push each other away from each other or do they pull each other together?
3. What happens when you touch the north pole of one magnet to the south pole of another magnet? Do they push each other apart or pull each other together?
4. Draw a picture of a bar magnet. Label the north and the south pole of your magnet.

Extra Credit

Lay a bar magnet on a smooth surface, with the north pole on the left and the south pole on the right. Now try to lay another bar magnet on top of it, again with the north pole on the left and the south pole on the right. What happened? Would there be a difference if the top bar magnet was facing the other way, with the north pole on the right?

Activity 2: Building a Compass

To build a compass you will need the following tools:

• utility knife or scissors
• ruler
• marker

For each compass you will need the following materials:

• one bar magnet
• 60mm x 15mm petri dish
• one straw (bendable or non-bendable)
• one needle (about 50mm long)
• enough water to fill petri dish about half way to the top (two to three ounces)
• small sticker
• compass (if desired)

Note: For this activity, the length of the needle should be slightly shorter than the diameter of the petri dish. The average length of the needles we used were about 50mm, so we used the 60mm x 15mm petri dish (60mm is the diameter).

Note: If you feel your students might be unfamiliar with the tools and materials, you should review the tools and materials vocabulary with them before assembling the Planetary Land Rover.

Steps

Step 1: Preparing the Petri Dish

1. Remove the lid from a 60mm x 15mm petri dish.
2. Pour water into the petri dish until it is about half full. This will serve as the body of the compass.
   

Step 2: Sizing the Straw

1. Using the metric end of a ruler, measure a straw.
2. Using a marker, make a mark at about 50mm.
   
3. Using scissors, cut the straw at the marked line. Keep the 50mm piece of straw.
   

Step 3: Magnetizing the Needle

1. Use a needle that is approximately the same size as the piece of straw (50mm).
2. Magnetize the needle by rubbing the needle anywhere on a magnet for 5-10 seconds. The needle is now a magnet too!
   

Step 4: Adding the "Needle" to the Compass

1. Place the magnetized needle into the piece of straw.
   
2. Place the straw (with the needle inside) onto the surface of the water. It should not break the surface of the water. If it does sink, dry the straw and needle before placing it back on the surface of the water.
   

Step 5: Determining the North Pole of the Needle

(Note: From now on the straw and needle combination will be referred to as the "needle" since it will be the part of your compass that determines direction.)

1. Use a bar magnet to determine the north and south poles of your "needle", which is also a magnet. To do this, place the south pole of your bar magnet near the "needle" of the compass. The end that is attracted to the bar magnet is the north pole of the "needle" (opposites attract). The other end of the "needle" is the south pole.
   
2. Once the north pole of the "needle" is determined, place a sticker on the north pole to distinguish it from the south pole.
   
3. Place the lid on the petri dish and get ready to use your compass!

Step 6: Using the Compass

1. The compass that you have just built can help you tell direction. The north pole of your compass will always point towards the direction north on the Earth. Since the sticker on your compass will always point to the north, you can figure out the other directions from this information.
2. To help remember the other directions, you might want to write the four directions (compass rose) on the lid of your petri dish. Regardless of the direction you are facing, twist the lid of the petri dish so that the "N" on the lid of the petri dish is lined up with the sticker on the "needle". The letter that is farthest away from you is the direction that you are facing.
   

Assessment

Our assessment methods were the same for Illinois and National Standards. Our assessment methods were the same and for Early and Late Elementary School students. What changed was the level of the questions asked and the discussion.We used informal assessment methods in the form of verbal questions and discussion. Formal methods of assessment included drawings, and written answers to questions, and the development of articles for the BOAST Kids Newsletter.

During the Lesson

The participants used inquiry strategies to successfully discover the properties of bar magnets and to build the compass. Then they tested the functionality of the compass and reported on its use. Throughout the lesson, the participants discussed the inter-relationships between science, technology, and society.

At the End of the Lesson

At the conclusion of the lesson, a discussion was held to determine the level of participant understanding concerning the properties of magnets and the construction and use of a compass. The discussion also encouraged students to think critically about the unique behavior of magnets and compasses.

Here is a sample of questions from that discussion:

• Why do the same poles of two magnets repel each other?
• Why do opposite poles of two magnets attract each other?
• What does a compass help us to determine?
• Why does the needle of a compass point towards the north? (The north end of the compass points to the south magnetic end of the Earth, which is located at the North Pole. Again, opposites attract!)

Each of the children who participated in the lesson was able to answer these questions at his/her own level.

Suggestions for expanding this activity

The Properties of Magnets Activity:

1. Use more than two magnets for this activity.
   • Will two magnets that are stuck together be a more powerful magnet?
   • How do multiple magnets behave around each other?
2. Perform the activity on different surfaces.
   • What happens when you perform the activity on a wooden surface?
   • What differences take place when you perform the activity on a metal surface?
3. Determine what magnets attract besides other magnets.
   • What objects are attracted to magnets? Do these objects have anything in common?
   • What objects are not attracted to magnets? Do these objects have anything in common?

The Building the Compass Activity

• Use other materials for the "needle" (the floating structure) of the compass, such as cork or styrofoam. Have participants determine what the best material is.
• Use other materials as the "body" of the compass, such as a cup or the lid of a jar.

Another way to build a compass:

1. Tie a string around one of the bar magnets.
2. Hold the other end of the string, allowing the magnet to hang freely. The north pole of the magnet will point toward the north! (Now bring another magnet near a suspended magnet and see what happens!)

Learning Standards

The following standards are from the Illinois Learning Standards, adopted by the Illinois State Board of Education on July 25, 1997. Take a look at the complete Illinois Learning Standards for Science, English/Language Arts.

Early Elementary

Late Elementary

As a result of their schooling, students will be able to:

National Science Education Standards that Apply to this Lesson

Take a look at the complete National Science Education Standards.