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qorizon
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So I have a cup of cold water placed on a table, as I hit the table with my palm I'm seeing concentric circles forming and disappearing on the water surface. Why is this happening? Are they waves or something else?
qorizon said:And why the concentric circles instead of just random waves?
The waves wouldn't be circular if the disturbance would not show up at one point (consider the case of throwing a stick horizontally into water-rectilinear waves)...but in this case(the cup) the disturbance turns out to show up at a single point (obeying natures symmetry).pixel said:Given the circular symmetry of the glass, and the assumption that the force transmitted by the table is uniform over the bottom of the glass, it might be more surprising if the waves weren't circular.
Rings in a glass of water are caused by variations in surface tension, which is the force that holds the surface of water together. When an object, such as a glass, is placed on the surface of the water, it disrupts the surface tension, causing the water molecules to move away from the object and create a depression. This depression appears as a ring around the object.
Rings only form in a glass of water when there is a difference in surface tension between the water and the object. If the surface tension of the water and the object are similar, no ring will form. For example, a plastic cup will not create a ring in a glass of water since both the water and the plastic have similar surface tensions.
Yes, the size of the ring in a glass of water can indicate how clean the glass is. A larger ring can suggest that the glass is not clean, as there may be oils or other contaminants on the surface that disrupt the surface tension of the water more than a clean glass would.
To prevent rings from forming in a glass of water, you can try using a different type of glass with a different surface tension, such as a plastic cup. Alternatively, you can try wiping the rim of the glass with a clean cloth before placing it on the surface of the water, as this will remove any oils or contaminants that may disrupt the surface tension.
Yes, the study of rings in a glass of water has practical applications in various industries, such as the food and beverage industry. Understanding how surface tension works can help in the development of products with specific properties, such as low-fat foods or drinks with a stable foam. Additionally, the formation of rings can also be used as a technique to measure surface tension and detect contaminants in liquids.