Why does cereal stick together

Arleen Sugano unravels the physics of this famous ballet move. The ability to do so has evolved independently throughout the animal kingdom, among over species of insects, spiders, birds, fish, reptiles, and mammals. Some insects spend their entire lives on the water surface; for other creatures, walking on water is a skill employed sparingly, often to avoid predators.

Although various motives for walking on water are mentioned, this page focuses ere on how rather than why creatures do so. Next Section ». Share: facebook twitter reddit whatsapp email classroom. Cynthia Silva. How can the meniscus effect explain how some insects and animals can walk on water? View discussion. Do you better learn science concepts through demonstrations, like watching this video on the Chee Surface tension is a property that makes the surface of a liquid act like a flexible membrane.

It results from various weak forces acting between liquid molecules. In a glass of water, most of the water molecules are surrounded by other water molecules and they all pull on one another. But like two equally matched opponents in a game of tug-of-war, the net effect is zero and nothing really happens. Where it gets interesting is at the surface, where water meets air, and along the sides of the glass. Water molecules at the surface experience a strong inward pull from water molecules beneath them but only a weak outward pull from the air molecules above.

So the surface of the water caves in slightly. Water near the side of a glass behaves differently. It curves to form what scientists call a "meniscus. For water, the meniscus is concave since water is attracted to the glass.

Viewed from the side, the surface of the water looks like a less exaggerated version of a skater's U-shaped halfpipe. Place a single Cheerio in a bowl of milk and its weight will cause the milk beneath it to dip slightly, forming a dent in the once smooth surface of the milk.

A second Cheerio placed into the bowl will form its own dent on the surface of the milk, and if the two Cheerios drift close enough to each other, they will appear to "fall into" one another, as if pulled together by an attractive force. All Issues. Switch Homepage. Sign in to Your Account. Haven't signed into your Scholastic account before? Create an account. Subscribe now.

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