Category : Science Projects And Inventions
YOU NEED:
A pen can be made to jump back into its cap as though pulled by a invisible hand, a magnet or a rubber band. Take the pencil and roll a square of paper around it like a tube about six inches (15cm) long. Tape it. Now tape the end of a rubber band to one end of the empty tube, as shown in the illustration and then push the rubber band into a tube. Procure a ballpoint pen with a cap shaped as in the illustration. Point first Insert the pen into the tube. Go through the motion of trying to hook its pointed end on the rubber band. Take the pen some way out of the tube. It zooms back into the tube as if jerked by the rubber band.
HOW DOES IT WORK?
just as you squeeze a watermelon seed your fingers squeeze the pointed cap. The illusion created is that something is pulling on the pen. Once you hand the pen to the friend, he or she will continuously try to make it go back into the tube without success.
FOOD FOR THOUGHT
Did you know that water can be hard or soft? Hard water is the water which contains calcium or chalk. You may have noticed that your pump water does not give a good soap lather. This is because the chalk from the earth is mixed with the water. If you want to make hard water into soft then you should boil it. This will make the chalk to come out and stick to the sides of the container like fur.
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