Water down a string science experiment : Fizzics Education


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Water down a string

Water down a string

Follow FizzicsEd 150 Science Experiments:

You will need:

  • Woollen or hessian string.
  • Food colouring
  • At least one clear tub (we like to use two)
  • 2 volunteers
  • A straw, pipette or eyedropper
  • A mess bucket and cleaning materials


Materials needed for experiment shown, Ball of string, Blue colouring , Pair of scissors, Piece of straw, Tub half full of water and pipette
1 Person adding blue food colouring to a jar half full of water

Add the food colouring to the water. You can run this science activity with pure food colouring which tends to be make the results more visible, however you will run the risk of food colour staining your fingers and other things!

2 Blue water getting extracted from a Blue jug of water by a piece of straw.

If you’re using the straw, place the straw into the water and then put your finger on the top of the straw. As long as you keep your finger over the straw the air pressure will keep the water in. This experiment is much easier though if you use a pipette or an eyedropper.

3 String getting stretched into the water while person adds water on the top of the string.

Stretch the string over the tub, angling the string upwards on one side. We actually use two tubs, so you can catch excess drops of water in the spot where you add water with the straw or eyedropper.

4 String getting submerged in water.

So… wet the string!

5 Blue water dripping off a piece of string into water while a person points to the water

Try the experiment again. With the wet string you find that after a couple of tries that the water will run down the string and into the tub!

6 String held by a hand while blue water drips down into a tub of water

You can show that the coloured water is running down the string quite easily as this colouration will end up in your tub of water 🙂

7 A man using a pipette to drop blue coloured water onto a taught strong that is suspended over a tray

Get the Unit of Work on Water Science here!

  • Explore the water cycle
  • Learn about cohesion, adhesion & capillary action
  • From water currents to floatation, join us to explore water science!

Includes cross-curricular teaching ideas, student quizzes, a sample marking rubric, scope & sequences & more

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8 A croed of seated students all with their hands raised in a V shape whilst follwoing Imogen doing the same (standing in front of the Fizzics desks)
9 Teacher showing how to do an experiment outside to a group of kids.

Online courses for teachers & parents

– Help students learn how science really works

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Why Does This Happen?

Water molecules really want to hang out with each other! Why? Water molecules have hydrogen and oxygen within them. When the hydrogen from one water molecule is near an oxygen atom of another molecule you get hydrogen bonding between the two molecules. If you scale this up to a droplet of water there are billions of water molecules, each wanting to be attracted to each other due to hydrogen bonding. It’s due to the hydrogen bonding between water molecules that we see that water droplets want to stick together (we call this cohesion).

Variables to try

  • Want happens if you add sugar or salt to the water? What if there is cordial in it?
  • Can you alter the temperature of the water?
  • What if you use milk or orange juice or honey?
  • Try varying the string type you used. Is nylon string better or worse? What about rope?

No matter which variable you try, just change one thing and keep the rest of the experiment the same to see if there is an effect. This is all part of the scientific method!

A man with a glove above a liquid nitrogen vapour cloud

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