SEASONS LAB for SchoolWires.notebook
October 08, 2014
Lab: The Reason for the Seasons
Oct 3­1:57 PM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
10/06/2014
Lab: Reasons for Seasons
Purpose: To model the reason for the seasons by demonstrating how the angle of the light affects its intensity on the surface. (In other words, How does the angle of the light affect the intensity of the light?)
Oct 8­6:22 PM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Experiment set­up flashlight
book with graph stack of books
paper taped to one side
protractor
Sep 25­1:31 PM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Lab: The Reason for the Seasons
Directions
page 1
Introduction: We have learned that the reason we have seasons on Earth is that
Earth is tilted on its axis of rotation 23.5 degrees. As Earth orbits the sun,
different parts of the earth receive more direct, concentrated sunlight at different
times of year. The purpose of this lab is to demonstrate how the angle of the
sunlight affects its intensity. Materials: flashlight
•
tape (masking & clear)
•
graph paper •
several textbooks
•
ruler
•
protractor
•
colored pencils (green, blue, purple, orange, brown)
•
Procedure:
Preparing the Light Source
1.
Make a stack of textbooks about 6 inches high on the lab table.
2.
Lay the flashlight on its side on top of the stack of books, lining up the
edge of the flashlight so it is close to the edge of the stack. Use masking
tape to tape the flashlight down so it can't roll around. (See
Figure 1)
Preparing the Surface:
1.
Use the clear tape to attach a sheet of graph paper to another textbook.
(Use an uncovered textbook, so the tape will come off easily when you
are done.)
2.
Turn on the flashlight. (Please, do not waste the flashlight batteries!)
3.
Hold the book with attached graph paper vertically in front of the
flashlight, as shown in Figure 1. Move the graph paper closer or farther
away from the flashlight, until the light on the paper forms a medium
sized, sharp circle about 2­3 inches in diameter. 4.
Measure the distance from the edge of the graph paper to the flashlight and
record this number as “starting distance” in your science journal. Make
certain to keep the graph paper at this starting distance for all testing!
Oct 8­5:41 PM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Procedure:
1. One person should hold the graph paper vertically (straight up and down) at the starting distance in front of the flashlight. 2. Another person should use a green colored pencil to draw around the outline of the light on the graph paper. Just draw around the most intense circle of light. Instructions
3. Observe the brightness of the light inside this outline and record your observations. 4. Place the protractor next to the graph paper so that the 90 º mark is lined up with your vertical textbook. Now tilt the textbook with attached graph paper 10 º. page 2
5. Use a blue colored pencil to draw around the outline of the light on the graph paper. (Again, trace only the most intense area of light.)
6. Observe the brightness of the light inside this outline, and record your observations and compare the brightness of the light at this angle to the previous outline. 7. Repeat steps 4–6 for tilt angles of 20°, using a purple pencil, 30°, using an orange pencil, and 40°, using a brown pencil.
Analyzing Your Data:
1. Draw the data table in your Journal. Use a ruler!
2. Count the approximate number of squares inside each light outline. Record your counts in the data table.
NOTE: For partial squares, estimate how much of the square is lit up; for example, if it looks like one­fourth of the square is lit up, add 0.25. If it looks like half of the square is lit up, add 0.5, and so forth. (Use decimals, not fractions!) 3. Send someone from your group to record your data in the Table on the Smartboard. When we have all groups’ data, we will calculate averages and you will record them in your own data table. Data Table: Number of Lighted Squares
Degree of tilt
0°
10°
20°
30°
40°
(green)
(blue)
(purple)
(orange)
(brown)
Number of squares within the outline
(your group)
Class Average Number of Squares within the outline.
Oct 8­5:41 PM
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SEASONS LAB for SchoolWires.notebook
20⁰
10⁰
October 08, 2014
0⁰
30⁰
40⁰
Note: Book with graph paper started straight up and down, and was tilted away from the flashlight. Oct 6­8:50 AM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
After drawing the
circles, everyone
counted the squares
within the outlines.
When a square was only
partly in the circle, we
counted pieces of them
and added them up.
Oct 3­10:05 AM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Number of squares within the outline Degree of 0°
tilt
(green)
10°
(blue)
20°
(purple)
30°
(orange)
40°
(brown)
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
Per. 1 Class Average 86.5
112
121
Sep 26­4:01 PM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Number of squares within the outline Degree of 0°
tilt
(green)
10°
(blue)
20°
(purple)
30°
(orange)
40°
(brown)
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
Per. 2 Class Average Sep 26­4:01 PM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Number of squares within the outline Degree of 0°
tilt
(green)
10°
(blue)
20°
(purple)
30°
(orange)
40°
(brown)
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
Per. 6 Class Average Sep 26­4:01 PM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Number of squares within the outline Degree of 0°
tilt
(green)
10°
(blue)
20°
(purple)
30°
(orange)
40°
(brown)
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
Per. 7 Class Average Sep 26­4:01 PM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Number of squares within the outline Degree of 0°
tilt
(green)
10°
(blue)
20°
(purple)
30°
(orange)
40°
(brown)
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
Per. 8 Class Average Sep 26­4:01 PM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Data Table: Average Number of Lighted Squares for each Class
Degree of tilt
0°
10°
20°
30°
40°
(green)
(blue)
(purple)
(orange)
(brown)
Period 1
86.5
112
121
137
151.5
Period 2
55.3
105.3
197.6
245.8
309.8
Period 6
50.5
65
96
118
145
Period 7
122
164
146
187
264
Period 8
130
223
293
340
460
Oct 8­6:00 PM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Construcng a Line Graph:
Step 1: Determine which variable belongs on each axis and label them.
The independent variable belongs on the x‐axis.
•
The dependent variable belongs on the y‐axis.
•
If it is a quantave variable, include the units in parentheses. •
Step 2: Decide on Scale and Interval. (Determine how you will fit the data onto your axes.) Step 3: Plot the points & connect them.
Step 4: Write the tle of the graph. The tle should be detailed and specific!
Oct 7­11:01 AM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Things to remember when making graphs by hand:
1. Use a ruler!
2. Use a pencil!
3. Intervals must be equal!
4. Be as neat as you can.
5. Make your axes and grids on the blue lines, not between them.
6. Don't forget to add specific labels and a specific, descriptive title!
Oct 7­11:02 AM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
What is wrong with this graph?
Graph
squares
0
10
20
30
40
50
60
degrees of the light
Oct 7­11:40 AM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Did you find all these errors?
title not descriptive
label is facing wrong way and is not descriptive
Graph
y-axis is not on blue gridline
squares
intervals on y-axis are not equal
x-axis not on blue
gridline and really
crooked
no numbers!
0
10
20
intervals on x-axis are not equal
30
40
50
degrees of the light
60
poor label!
Oct 7­11:40 AM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
This graph of data from 2013 is an example of a good graph:
Reasons for Seasons Lab: Relationship Between Angle of Light and Number of Lighted Squares 400
375
350
325
Number of Lighted Squares
300
275
250
225
200
175
150
125
100
75
50
25
0⁰
10⁰
30⁰
20⁰
40⁰
Angle of Light
Oct 3­10:04 AM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Your task is to make a double line graph that shows your own group's data in one color
and your class's average in a different color.
Reasons for Seasons Lab: Relationship Between Angle of Light and Number of Lighted Squares 400
375
350
325
This is the basic template for your graph, except you must decide how to number and scale your y­axis according to how you can best fit your particular data onto the graph. Number of Lighted Squares
300
275
250
225
200
175
150
125
100
75
50
25
0⁰
10⁰
20⁰
30⁰
40⁰
Angle of Light (degrees)
Oct 3­10:04 AM
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SEASONS LAB for SchoolWires.notebook
October 08, 2014
Comparison of Data from 2013 and Period 1 & 2 from 2014
Reasons for Seasons Lab: Relationship Between Angle of Light and Number of Lighted Squares 400
375
350
325
Number of Lighted Squares
300
Key
275
250
2013 data
225
2014 data
200
175
150
This is an example of a double line graph. You will also need to include a key for your graph. 125
100
75
50
25
0⁰
10⁰
30⁰
20⁰
40⁰
Angle of Light
Oct 3­10:04 AM
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Attachments
clipboard.bmp