Slow Waves |
Watch waves in slow motion with this simple kitchen science experiment!
You will need one or two clear bottles with secure lids, water, food colouring and vegetable oil.
This article from Scientific American has full instructions for this experiment, including clean-up.
What is going on? The driving force for the wave is related to the difference in pressure on the water beneath the deep and shallow areas (the crest and trough of the wave).
When the space above the water is filled with air, the pressure on the water beneath the deep part is much greater than the pressure on the water beneath the shallow part. This creates a strong driving force and the wave moves fast.
The vegetable oil is less dense than the water but much more dense than the air. When the space above the water is filled with oil the difference in the pressure on the water underneath the crest and trough is less. The driving force is smaller and the wave moves more slowly.
This article from Scientific American has full instructions for this experiment, including clean-up.
What is going on? The driving force for the wave is related to the difference in pressure on the water beneath the deep and shallow areas (the crest and trough of the wave).
When the space above the water is filled with air, the pressure on the water beneath the deep part is much greater than the pressure on the water beneath the shallow part. This creates a strong driving force and the wave moves fast.
The vegetable oil is less dense than the water but much more dense than the air. When the space above the water is filled with oil the difference in the pressure on the water underneath the crest and trough is less. The driving force is smaller and the wave moves more slowly.