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