Shadow Length Change
Why does the length of a shadow change during the day?
Try this (you will need a ruler, pencil and two sheets of paper):
1) draw two upright lines of exactly the same height (about 3cm
in height should do), one line per piece of paper.
2) For one of the lines draw a point or dot at a distance of, maybe
20cm to the right and about 2cm higher than the top of the original
3) Now, draw a line from the dot to the top of the upright line and
continue the line until the line you are drawing is at about the same
height as the bottom of the upright line. The distance of the end of
the line you've just drawn to the bottom of the upright line is the
length of the "shadow" of the upright line.
4) Do the same for the second line, BUT draw the point (or dot) at a
distance of maybe 10cm to the right and 5cm higher than the top of the
upright line. Then draw the line as in #3 above.
5) You should note that the "shadows" are of different lengths. Can you
Greg (Roberto Gregorius)
Click here to return to the Astronomy Archives
Update: June 2012