students observe how their (sun) shadow changes throughout the day and seasons
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\. Me and My Shadow. Students observe how their (sun) shadow changes throughout the day and seasons. 90 o. Me and My Shadow. - PowerPoint PPT PresentationTRANSCRIPT
Students observe how their (sun) shadow changes throughout the day and seasons.
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90o
Me and My ShadowMe and My Shadow
Me and My ShadowMe and My Shadow
A shadow is created when an object blocks a light source, leaving an unlit area. The size of the shadow depends on the size of the object and the position of the light source.
Shadows and SunlightShadows and Sunlight
90o 30o
The shadow you create by blocking sunlight changes through the day as the position of the sun in the sky changes.
Shadows and SunlightShadows and Sunlight
You can determine the position of the sky by using your height, your shadow length and some simple trigonometry
Angle = ArcTan (your height / your shadow’s length)
your
hei
ght
your shadow’s length
If your height = 100 cm and your shadow’s length = 100 cm:
Angle = ArcTan (100 cm / 100cm) = ArcTan (1) = 45 degrees
Shadows and SunlightShadows and Sunlight
The angle can also be determined graphically with a protractor. Graph as shown below with X=shadow length, y=height
100
cm
100 cm
45o
Shadows and SunlightShadows and Sunlight
The angle can also be determined graphically with a protractor. Graph as shown below with X=shadow length, y=height
100
cm
30 cm
73o