Materials Included In Kit

Additional Materials Required

Prelab Preparation

1. Using a compass, align the rope in a North–South direction. The number “1” should be on the South end of the rope and the number “20” should be on the North end of the rope.
2. Each end of the rope may be tied to a weight or, if loops were created in step 9, a stake.
3. Copy the Course Cards.
4. Cut out the Course Cards.
5. Assign each group of students a course card. Note: The first number on the course card represents the course size (see Lab Hints) and the second number represents the starting point on the rope.

1. Measure 40 cm from one end of the rope.
2. Gently twist the rope to slightly unbraid the strands. Note: See the Lab Hints section for an alternative method.
3. Insert a twist tie between the braids in the rope (see Figure 1).
   {13248_Preparation_Figure_1}
4. Twist the braids in the rope back together.
5. Thread the twist tie through the hole of one of the plastic orange tags.
6. Twist the twist tie together and cut off the excess length (see Figure 2).
   {13248_Preparation_Figure_2}
7. Repeat steps 2–6 for the remaining plastic orange tags, placing each tag 1 m apart.
8. Using a permanent marker, label each survey tag (both sides) with a number (1–20). Note: The answers listed for this course reflect the use of the numbers 1–20 with “1” on the South end of the rope and “20” on the North end of the rope. Letters or symbols could be used in place of numbers.
9. (Optional) Using the extra rope at each end of the rope-tag assembly, make a loop out of the end of the rope and secure it closed using a twist tie (see Figure 3).
   {13248_Preparation_Figure_3}

Safety Precautions

Although the materials in this lab are non-hazardous, please follow normal laboratory safety guidelines. Remind students to wash their hands thoroughly with soap and water before leaving the laboratory.

Disposal

All materials included in this kit may be saved for future use.

Lab Hints

• Enough materials are provided in this kit for 40 students working in pairs. All materials are reusable. This laboratory activity may be reasonably completed in one 50-minute class period.
• Manufacturers may change the rope braid design without notice. If untwisting the strands is difficult, use paper clips instead of twist ties to attach the survey tags.
• Laminate the course cards so they can be reused.
• The course was designed so it can be used in a small, medium, or large area. To use the course in a small area such as a classroom, use the cards with a course number that starts with the number 1; this course requires an area of approximately 6 m². To use the course in a medium area such as a gym, use the cards with a course number that starts with the number 2; this course requires an area of approximately 10 m². To use the course in a large area such as to football field, use the cards with a course number that starts with the number 3; this course requires an area of approximately 20 m². The small and medium courses will accommodate fewer students or larger groups.
• Students could measure their stride and convert the distance between each point into stride lengths. This is not as accurate, but provides a lesson in unit conversion.

Teacher Tips

• This activity can be used to teach distance measurement, magnetism, Earth’s magnetic field, degrees of a circle and the basics of orienteering.
• The students must know how to use a compass prior to attempting this activity.
• Relate using a compass to navigate a distance with the use of treasure maps to find buried treasure or with an explorer traveling by ship when the stars are not visible for nautical navigation.
• This activity provides a great opportunity to partner with the physical education department.
• To calculate a grade, the teacher could deduct 5 points for each tag away from the correct tag a student writes on the worksheet.

Answers to Questions

1. Name two factors that may affect a compass reading.
   Student answers will vary but may include metal (iron, steel, cobalt or nickel) objects, misreading the compass, measuring the distance incorrectly, moving the cup marker, misreading the survey tag, etc.
2. In what direction does a compass needle point?
   North and South
3. Would having steel or iron nearby affect a compass reading? Explain.
   Yes, the magnetic compass needle will attract steel and iron and may provide a false reading for North by pointing in the direction of steel or iron object or deposits.
4. What is the scale of the compass?
   0° to 360°
5. Give the value in degrees for each cardinal point of the compass; that is, North, South, East and West.
   North—0°, South—180°, East—90° and West—270°.

Teacher Handouts

13248_Teacher1.pdf

Introduction

Navigate the “Compass Challenge” using measurement skills and the natural magnetism of the Earth. Using a compass and a course card, navigate from an assigned location reporting at least three “points” along the way until you reach the end of the course. The only way to complete the course and reach the final destination is to properly use a compass and accurately measure the distances traveled.

Concepts

• Distance measurement
• Compass reading/navigation
• Magnetism

Background

The compass is an instrument used to display the direction of the Earth’s magnetic field. The compass was first used in China during the 3rd century BC. The first compasses were made of magnetite, or lodestone, a mineral that aligns itself in a North–South direction. Magnetite was replaced with magnetized needles in the 8th century AD. Compasses were first used to orient the direction of buildings and other structures with the natural forces of the Earth. Later they became popular with navigation, especially on the open seas. Prior to the invention of the compass, seafarers relied exclusively on the sun and stars for navigation, which caused delays during overcast weather.

The modern compass consists of a magnetized pointer on a pivot that is free to align itself with the Earth’s magnetic field. The compass is divided into 360 units called degrees, or 360°. The compass is also divided into four primary directions called cardinal points. These points are North (0°), South (180°), East (90°) and West (270°). No matter where one is on the Earth, the compass needle will always point toward the North Pole.

Experiment Overview

By using a compass properly and correctly measuring distances, teams will find the correct destination on this compass measurement challenge.

Materials

Safety Precautions

Although the materials in this activity are non-hazardous, please follow normal laboratory safety guidelines.

Procedure

1. Begin the course by standing at the number, letter or symbol that is written on the orange tag, as assigned by the teacher.
2. Using a compass, one team member finds the first bearing listed on the assigned course card.
3. The second team member places the cup marker in line with the first team member, in the direction of the compass bearing.
4. The team then moves the required distance from the starting point to the first destination point listed on the course card.
5. From each destination point, repeat steps 2–4 to find the next destination point until the course has been completed.
6. On the worksheet, record the number, letter or symbol for both the starting point and the destination point as well as the closest point each time the rope is crossed.

Student Worksheet PDF

13248_Student1.pdf