26 March 2009

Another look at paper

We were wondering; is the strongest paper also the one that sucks up the most water (or most absorbent)

Virginia thought back to when we had looked at different kinds of paper using a microscope.  She remembered that the fibres of each piece of paper left holes and that paper towel had bigger holes than A4 writing paper.  She also noticed that paper towel is thinner than A4 writing paper.  She thought that meant the water would probably go into the holes (a bit like in a sponge).

And how would we test to find out whether she was right?

We would take three identical (same width, same length) strips of the paper we used before (how strong is paper?)…..

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those being newspaper, paper towel and A4 writing paper - and attach them to a strip of masking tape.  This we would stick to the back of a chair so that the ends dangled downwards.

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Next we would rig up a dish of water beneath the paper strips so that the ends dipped into the water.

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We would leave the paper strips in the water for exactly one minute (which of course we timed accurately with a stop-watch).

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Then we would measure how far up the paper the water had crept in one minute.

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The newspaper:

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The A4 writing paper:

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The paper towel:

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Then we would record our results in a table.

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Which type of paper did we find was the most absorbent?  Why do you think this might be?  Next time you wash your hands, think; which paper would I choose to dry my hands with?

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