Angle of the Sun

NOTE: This activity is in the developmental stage, though almost complete. Graphics, formating, & proof reading have yet to be completed. Everything else is fully funcional, including the calculator and database tools. So, go ahead and use it!!

Purpose

The purpose of this activity is allow students to practice measuring, communicating & collaborating with others on a research project, analyzing data, and drawing possible conclusions from/about any patterns they discover.

Introduction

Most people think that the sun is directly overhead at noon. The truth is that this rarely happens. As a matter of fact, there are many places where this never happens (like Waukesha, Wisconsin). So where exactly is the sun in the sky? If you've never thought about it, you probably have never noticed. In this activity, you will measure how high the sun actually is above the horizon and then submit your findings to a database. Next, you'll look at other students' data and see if you notice any patterns. The rest of this page gives you the specific instructions you should follow.

This activity works best if many people make measurements at exactly the same time of day on (or close) to the same day. This being the case, you may want to contact friends, relatives, etc. who live in different states or countries and have them help you out by making measurements & posting their results as well.

Measuring the Angle of the Sun

First, you need to measure how high the sun is above the horizon. Here's how you do that:

1. Get a meter stick.
2. Go outside (on a sunny day) and put one end of the meter stick on the ground with other other end sticking straight up as is being shown in the picture below.
3. On the ground, mark the beginning and end of the shadow.
4. Measure the length of the shadow.
5. Record the length of the shadow in meters. It may be easier to measure how many milimeters long the shadow is and then convert millimeters into meters by moving the decimal point 3 spaces to the left.
6. Record time at which you measured the length of the shadow.

Calculating the Angle of the Sun

Now that you know the length of the meter stick's shadow, plug your measurement into the calculator below to determing the angle of the sun above the horizon.

In case you were wondering, the equation used to calculate the sun's angle above the horizon from the shadow length is

angle of sun above horizon = tan^-1

Find Your Latitude

The last piece of information you need is your latitude (and longitude). If you don't alread know it, follow the steps below to find it.

1. Go to mapblast.com .
2. Type in the address where you took your measurements.
3. Click the Create Map button.
4. Find your latititude (and longitude) just above the upper-right corner of the map.

Report Your Data

Simply fill out the form below and send it on its way to add your information to the database.

View & Analyze Other Student's Data

You're almost done. Now that you have collected and submitted your own data, it's now time to look at other student's data from around the country/world. Click here to see all the data submitted by students. Your job now is to analyze the data to see if you notice any trends or patterns. One great way to analyze data is to use a graph. As a matter of fact, the first thing you will do is graph the angle of the sun compared to latitude. To do this, follow the instructions below.

1. Find your own data in table of data submitted by all students (it will have your initials & will probably be near the end of the list).
2. Find measurements from other days close to the day you made your measurements.
3. From those days, identify measurements that were taken at the same time of day as you took yours.
4. Record the latitude and sun's angle into 2 columns on a spread sheet.
5. Graph the two columns of data.
6. Notice any patterns or trends that show up on your graph. Why do you think these trends exist?
7. Look at the sun's angle and latitude information and compare it to the typical temperatures reported for that area. Are there any patterns or trends? If so, why do you think they exist?

Questions to Consider

Discuss the following questions with your classmates.

• Why did you have to graph data from students who took measurements near the same day as you did?
• Why did you have to graph data from students who took measurements at the same time of day as you did?
• What might your graph look like if you used data that was gathered at a different time of the day?
• Why was it important to know if the measurements were taken while daylight savings time was in affect?
• What other time of the year would give you similar results as the measurements you took today? Why?

Wrapping It Up

To receive credit for completing this activity, write a summary of your findings & present it to your teacher. Your summary should include the following information.

• The measurements and calutations you made.
• A copy of your graph.
• A discussion of what your graph is showing.
• An explanation for why your graph is showing what it is showing.
• Any patterns you noticed between the sun's angle, latitude, and typical temperatures with an explanation as to why those patterns might exist.
• A reasonable explanation for one of the "Questions to Consider" listed above.