EXERCISE 11 

 DOES THE SUN'S POSITION AT NOON CHANGE FEOM DAY TO DAY ? 



Materials. A piece of cardboard about 10 inches square. 



Directions. The members of the class should work together on this exercise, but each pupil 

 should write notes independently. 



Place a large piece of cardboard with a hole about three eighths of an inch in diameter in the upper 

 part of a south window and fasten it securely in place. When the sun is shining brightly notice on 

 the floor or desk the spot of light made by the sun shining through the hole in the cardboard. Trace 

 the position of the spot on the floor with a pencil or crayon at intervals of five minutes. On the next 

 or some succeeding day, at the same hour, note whether the spot is at the same distance from the 

 window as at first. If not, what does this indicate regarding the change in elevation of the sun in 

 the sky ? 



Additional problems. Why is it that when you trace slowly the spot of light referred to above, your mark 

 when you finish does not coincide with the mark with which you began ? 



If in performing the above experiment the spot of sunlight moved farther from the window or nearer 

 to it, do you think the direction of this movement would be the same for twelve months ? Why ? 



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