Experiment: Walking Water.
Today we learnt all about Capillary Action.
What
is Capillary Action?
You've just come in from playing in the hot sun and
you decide to pour yourself a cold glass of water. Before you can drink it all,
you accidentally knock over the glass and spill some water. You grab a paper
towel and put it over the puddle. The water immediately soaks into the paper
towel and the counter is dry. You've just used capillary action to clean up
your mess!
Capillary action happens when a liquid, like water,
moves up through a hollow tube or into a spongy, solid material.
Water moving up
through paper towel due to capillary action
|
This is how
flowers and plants move water from the ground beneath them, up through their
stems and into their petals and leaves.The paper towel is very 'absorbent':
which means there are enough gaps in its fibre for the water to move through
easily and quickly. The adhesive force between the water and the paper towel is
stronger than the cohesive forces inside the water itself.
We then had fun experimenting with mixing the primary colours.
