ALCA Members PLC Domains Data Standards Map Plan Curriculum Assessment Strategies

High in the Sky! a Bird...a Plane...No! the Sun! Copy

This lesson is really quite simple, with very little equipment needed. It is a variation of the "height of the flagpole" activity. The advanced mathematical concepts of tangent and arctangent are introduced, by using a tangible triangle. Enrichment or expansion of the activity will help students observe that the sun is at different levels above the southern horizon, depending on one's location north or south of someone else.

Required Resources

  • Equipment Some type of upright rod or pole (fence post, tether ball pole, flag pole) that the students can use for physically measurements. Notebook for data. Scientific calculator.

  • Sun Angles data form - Keep the measurements in this data form for the duration of the activity, being sure to have at least four different measurement times. The results can be shared with students in other areas.

  • Checklists (Rubrics) - This rubric is designed to use as a student checklist or a teacher evaluation tool. It is based on a point grading system. To calculate a percentage grade, divide the points earned by the points possible. Total Points Possible: 20

Optional Resources

  • "Sun's Web" internet site

    • The source of this material is Windows to the Universe, at the University Corporation for Atmospheric Research (UCAR), the Regents of the University of Michigan.
       

Steps

  1. Background Information

    THEORY: The upright rod/pole and its shadow make two sides of a special type of triangle called a right triangle. A right angle is one that measures 90 degrees. This angle is the one between the rod/pole and the ground. By mentally connecting the end of the shadow with the top of the rod/pole, you complete this right triangle. This mental connection (between the end of the shadow and top of the rod/pole) points directly at the sun. Mathematics allows us to calculate the angle made between the ground and the imaginary line from the ground to the top of the rod/pole.

    CALCULATION: You will need a scientific calculator for the calculation. The length of the rod/pole is called the side opposite, and the length of the shadow is called the side adjacent. Tangent is the ratio (fraction) of the side opposite (rod/pole) divided by the side adjacent (shadow). This fraction can then be changed into the angle by finding the arctangent. Most calculators require you to push an alternate mode key, then the tangent key. Record this number on the same line as your other data. Do this for each set of measurements as required by your teacher.

  2. Setup

    1. Your measurements should be kept in some type of notebook that can be saved over the next few months. Additionally, the information gleaned from the measurements should be recorded in the data form for this lesson.
    2. Determine what measurement system (Metric/English) that you are going to use for the duration of this activity.
    3. Your teacher will choose a rod or pole that will be the main focus of this activity.

  3. Measurement

    1. In order to show the sun's movement, be certain to make these measurements at four different times, perhaps monthly or about every six weeks.
    2. Write down the date and exact time (watch out for daylight savings time) of each measurement.
    3. Measure the height of the rod/pole, being as exact as possible. Write this measurement down in your data notebook and/or data form.
    4. Measure the length of the rod's/pole's shadow and record this in your data notebook and/or data form.

  4. Followup

    Answer the Engaging Questions found in the Teacher's Guide of this lesson.

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