What is the heaviest thing you can pick up by using your thumb and finger? Paper, a hairbrush, the dog’s leash, and even a book (if it isn’t too heavy) are things you can lift this way.
If you use your entire hand, though, you can pick up things that weigh even more. And if you use both hands, you can lift even more weight, right? Do you know why this is so?
You can pick up more weight with two hands than you can with two fingers because of weight distribution. The weight of the object you are picking up is distributed or stretched across the size of whatever you are using to pick it up (2 hands, 1 hand or 2 fingers).
Weight distribution works with other things, too. It even works with paper. Yes, if the weight distribution of the paper is correct, a single piece of paper can hold up a book that weighs many times more than the paper does.
If you don’t believe that, you will change your mind after doing the following experiment.
THINGS YOU NEED
- 3 sheets of paper (the paper you use in a printer or construction paperwork just fine)
- Scale (optional)
- Kitchen table or desktop
- CD or DVD case
- Book (paperback or hardback off your bookshelf is fine)
- Pencil and paper to write on (optional)
HERE IS WHAT YOU DO
- If using a scale in this experiment, weigh the magazine, CD, or DVD case and the book.
- Write down how much each item weighs.
- Stand one piece of paper on your table or desk—holding it upright.
- Try to balance the magazine, the case, and the book on the edge of the paper (one item at a time, of course).
- Roll one piece of paper into a tube shape about as big around as the cardboard tube paper towels and wrapping paper come on. Tape the edges so it does not unroll.
NOTE: Roll the paper from the longest side.
- Try to balance each of the items on top of the tube one at a time.
- Fold another sheet of paper in half to make a tent.
- Stand it so that the fold is on top.
- Try to balance each of the items on the fold.
- Adjust the tent so that the fold is on the side—as if you are opening a birthday card.
- Try to balance each of the items on the paper.
NOTE: You may need to adjust how wide the tent is open to fit the size of the item you are trying to balance.
- Take the remaining piece of paper and form another tube.
- Stand the paper tubes side by side.
- Balance the magazine on top of both tubes.
- Add the CD or DVD case.
- Now add the book.
- Repeat steps 4, 5, and 6 using the same objects, your first finger, and then the palm of your hand.
WHAT JUST HAPPENED
The paper weighs the same whether it is flat, rolled or folded, but by rearranging how the weight of the paper is distributed, the paper can hold or support more than its own weight.
TRY THIS TOO
- Repeat the experiment using different items.
- Repeat the experiment folding the paper into different shapes.
- Make several paper tubes and build a pyramid from the tubes and magazines or books.
WHAT YOU LEARNED BY DOING THIS EXPERIMENT
- Plants are safe and natural ways to dye fabric and make paint.
- Changing the weight distribution of something changes its strength.
- The weight of an item does not always have to be less than the item is resting on.
- Changes sometimes make the impossible possible.