Objective
Explain how changes in angle of the sun's rays striking the Earth change energy and
daylight.
Seasons Four Times of the Year
(an activity from Janice Van Cleave’s A+ Projects in Astronomy)
Question
How does the angle of light change the estimated area covered by the light?
Materials
 Flashlight
 Graph paper
 Pencil
 Protractor
Safety Concerns:
Flashlight. Do not shine
flashlight in other student’s
eyes.
Procedure
1. Lay the graph paper on a platform.
2. Turn on the flashlight and hold it so it is pointing straight down (90o) on the
graph paper.
3. Draw around the bright center circle of light you see on the paper.
Objective
Explain how changes in angle of the sun's rays striking the Earth change energy and
daylight.
4. Count all the squares that are at least halfway in the light. Look again at the
example on the other side of the paper.
5. Calculate the estimated area covered by the light. Multiply the number of
squares checked by the area of each square. For example:
 Area of the lighted circle = estimated squares x area of each square
 = 21 x .0625 in
 = 1.31 in2
6. Repeat at the angles on the worksheet.
7. Compare your results. Be prepared to answer to present your results to the class.
Objective
Explain how changes in angle of the sun's rays striking the Earth change energy and
daylight.
Group Members _____________________________________________________
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Absent _____________________________________________________________
Seasons Four Times of the Year
(an activity from Janice Van Cleave’s A+ Projects in Astronomy)
Complete the table.
Light Angle
Number of Squares
Checked
Multiply by
Total Area
Covered
90o
x .0625 in2
in2
60o
x .0625 in2
in2
45o
x .0625 in2
in2
30o
x .0625 in2
in2
Explain how the angle of sunlight affects the area covered by light.
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