Interactive Primary Bulletin 38 | ||
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About face Tent-fold a piece of cardboard and draw or print a horizontal arrow on it. Place it about 15 cm behind an empty straight-sided glass and challenge a member of the class to change the direction of the arrow without touching the glass or the card. If they fail, fill the glass with water from a jug/bottle which has been sitting inconspicuously on the table. Now, when you look through the glass, the arrow should appear to be facing in the opposite direction. What is happening to the light from each end of the arrow as it passes through the water? The view from above may help to explain how a reversed image is produced. The water in the glass, which appears circular from above, acts like a lens to bend the light rays. | ||
 Figure 12 - Without water |
 Figure 13a - With water |
Figure 13b - Move the mouse pointer over the pic to see movie |
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