Science Projects And Inventions



  • An empty kitchen towel roll
  • Scissors


Before discarding the cardboard tube after you have exhausted the roll of toilet paper take a good look. It is difficult to believe that the circumference of the cylindrical tube is longer than its length. But the fact is that it is, longer than the tube's length! Cut the cylinder open along a dotted line as shown in the illustration. The rectangle that you are left with has one side that was the tube's circumference. The other side was the tube's length. Now if you fold one edge of the cardboard over the top of the other edge, you will find out that the circumference is about an inch longer than the length of the erstwhile tube.


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