Metastable Equilibrium.

The image shows a hammer balanced on a matchstick, which is balanced on another matchstick, which is balanced on another matchstick, and so on. This is a classic example of a metastable equilibrium.

In a metastable equilibrium, an object is in a state of equilibrium, but it is not stable. This means that a small disturbance can cause the object to fall out of equilibrium. In the case of the hammer, a small vibration or bump could cause the matchsticks to topple, and the hammer would fall.

The reason why the hammer stays balanced on the matchsticks is because the matchsticks are very thin and flexible. This means that they can easily bend and flex to accommodate the weight of the hammer. However, if the matchsticks are bent too much, they will eventually break, and the hammer will fall.

Metastable equilibria are common in nature. For example, a pencil balanced on its point is in a metastable equilibrium. A small disturbance, such as a breeze, can cause the pencil to fall over.

Metastable equilibria are also important in many scientific and engineering applications. For example, metastable materials can be used to create new materials with unique properties. Metastable equilibria are also used in the design of bridges and other structures.

In conclusion, the image shows a metastable equilibrium. This is a state of equilibrium that is not stable, and a small disturbance can cause the object to fall out of equilibrium. Metastable equilibria are common in nature and are important in many scientific and engineering applications.

**Key Points:**

• Metastable Equilibrium: A state where a system is balanced but unstable.
• Small Disturbance: Even a minor disturbance can cause the system to fall out of equilibrium.
• Hammer and Matchsticks: A classic example of metastable equilibrium. A slight vibration can topple the structure.
• Flexibility: The matchsticks' flexibility allows them to accommodate the hammer's weight, but excessive bending can lead to breakage.
• Natural Examples: Pencils balanced on their points are another example of metastable equilibrium.
• Scientific and Engineering Applications: Metastable materials and structures are utilized in various fields.

Mesomorphic State

What do you mean by Mesomorphic State?

When some solids are heated, they melt at a definite temperature and transform into a turbid liquid. When this turbid liquid is heated at a higher temperature, it is converted into a clear, transparent liquid. When this liquid is cooled, the reverse process starts, and at the same temperature, the clear liquid is converted to a turbid liquid. On further cooling, crystallization of the turbid liquid starts at the same temperature. The properties of the turbid liquid are like those of a crystalline solid, for example, turbid liquid is anisotropic, like a crystalline solid.

Due to this similarity of turbid liquids with crystalline solids, these are known as liquid crystals. Most of the properties of the turbid state are more similar to the liquid state rather than the solid state. Hence, these liquids can be considered as an intermediate state of solids and liquids, which is known as the mesomorphic state.

The definite temperature at which a solid is converted to a turbid liquid is known as the transition temperature, and that definite temperature at which a turbid liquid is converted to a clear liquid is known as the melting point.