This viscosity experiment is a fun way to discover how different liquids flow. Or just to have a race with ketchup and other kitchen ingredients!
The rate at which different fluids flow can vary considerably, this is called resistance to flowing viscosity.
We did this on a big board in the garden, but it works just as well on a much smaller scale. Chopping boards are perfect to act as a ramp.
Viscosity Experiment for Kids
What you need
- Ramp – chopping board or paper covering something else.
- Lquids to test, today we used oil, water, corn syrup, passata, treacle and ice cream sauce
- Containers for the liquids, we used old yoghurt drink bottles
We thought carefully about the best way to time the different liquids. Initially we thought we would let them all run down the ramp at the same time and see which reached the bottom first, but decided it would be too hard to release them all at the same time and difficult to time. So, we drew two lines on the ramp and recorded the time taken for each liquid to pass between the lines.
Viscosity Experiment Instructions
- Pour the liquids down the ramp one at a time.
- Start the timer as the liquid passes over the first line and stop when it passes the second.
- Repeat for all liquids.
Make your own ramp
If you’re doing this in a school or with lots of children a wipe clean ramp is a good idea. I made this one for a school science fair by covering a big sheet of cardboard with contact paper ( sticky back plastic ).
Let’s make it a fair test!
The same volume of liquid should be used for each substance, we used 50ml.
Only start the timer once the liquid has passed the first line.
If the ramp falls over mid experiment, make sure it has the same gradient as before to keep the test fair.
To be more accurate you could repeat for each liquid 3 times and find the mean of the times.
More Easy Science for Kids
There’s a similar activity in Snackable Science where we race different ketchups to investigate whether different brands flow at different speeds.
If you enjoyed this experiment we’ve got lots more easy outdoor science experiments and investigations you might like and some great kitchen science ideas too!