When a coin floats on top of the water in a glass, it’s primarily due to surface tension.
Here’s a closer look at how it works:
- Cohesion of water molecules: Water molecules are attracted to each other, a property known as cohesion. This attraction is especially strong at the surface of the water, creating a sort of invisible “skin” or elastic film.
- Uneven forces: Water molecules below the surface are pulled equally in all directions by neighboring molecules. However, molecules at the surface are pulled inward and sideways by other water molecules, but not upward by molecules above them (as there are none).
- Surface Tension: This inward pull creates a net attractive force at the surface, resulting in surface tension.
- Floating: When a coin is carefully placed on the water’s surface, the surface tension is strong enough to support the coin’s weight, preventing it from sinking. The coin essentially rests on this “skin” created by the cohesive forces between water molecules.
- Breaking Surface Tension: If the coin is pushed down or the surface tension is disrupted (for example, by adding soap or touching the coin), the coin will sink because the surface tension can no longer counteract the force of gravity.
In essence, surface tension acts as an upward force, counteracting the downward pull of gravity on the coin and allowing it to remain afloat.
Why is a coin able to float on top of water in a glass?
It is all because of surface tension. Surface tension is a property of liquids that is a result of cohesive forces. Translated: cohesive forces are those forces that hold things together.
Why do coins float on water?
Thanks for asking. So coins are made up of metal. And it is a very dense substance. And it’s packed within a very small volume. And thus it sinks.
Why the coin is able to float on top of the water in this glass quizlet?
Good point! Particles at the surface of the water are hence pulled downwards because there is a net force. This net force creates a surface tension that allows the coin to float on its surface.
Why does a coin appear raised when placed in a glass of water?
When the light comes out from the beaker, refraction occurs. As the light travels from denser (glass) to rarer (water) medium it will bend away from the normal. As a result, the apparent position of the coin will shift upwards and the coin appears to be raised.