Thermodynamic-ally we can understand the isolated system as a system that does not allow any energy and matter from its surroundings.
Let us understand 3 isolated system examples:-
- Head On Collision Of Two Cars
- The Collision Of Balls On Billiards Table
- Our Entire Universe
- A Thermos Flask
Head On Collision Of Two Cars
We can see a car as an example of an isolated system because the car neither pushes it from inside nor on the opposite side. Let us understand through the example of two cars collision, which could be an excellent example of an isolated system.
The two cars face friction while moving on-road and in their head-on collision. Here it is not an isolated system as an external force acts upon it. But if the friction is taken out of the scenario, then the system of two becomes an isolated system. This happens because the forces they face are canceled in their collision, and no external force acts.
As of now, there will be no exchange of heat or any energy and no exchange of matter. It becomes an isolated system.
The Collision Of Balls On Billiards Table
As we know, an isolated system is that there is no exchange of energy and matter from its surrounding. Let’s go through the following to examine the collision of two balls on the billiards table as an isolated system.
In an isolated system, the collision between the billiards ball its momentum can be neglected as long its friction is nearly zero. By this, the forces which act upon them will only be due to the contact force between them as the frictional force is now negligible. Now, these forces between them are internal, with no external force, and energy is within them.
Hence, in the collision in billiards ball, too, there is no exchange of energy and matter. So we can say that it is an isolated system.
Our Entire Universe
For our universe to be an isolated system, it must complete the circumstances necessary to be called an isolated system which means no exchange of energy and matter.
The universe has had no boundary, The total mass of the universe is constant, The total energy of the universe is constant, and the universe has no surroundings. By this, we can say that the universe fulfills all conditions needed to be called an isolated system. Hence universe is an isolated system.
A Thermos Flask
Thermo flask as an insulated system can be understood by knowing what a thermos flask is and how it is made.
A thermos flask can be assumed as a highly isolated flask in a vacuum. Mostly the thermos flask available is two-layer. A vacuum separates the innermost chamber within the glass layered with the outer chamber, where the outer chamber is made of either plastic or metals.
The glass in the flask is fringed with a reflective metal layer. The unbreakable flask, which we usually see, comprises two layers of stainless steel with vacuum and a reflective layer in it. The thermos flask also has a compact screw at the top.
These are the features of a thermos flask. Based on this, now let us know. How does it act as an isolated system? The above features are given of a flask, which prevents the flow of heat transfer. This is possible because of conduction, radiation, or convection.
As we know, the transfer of heat is possible through conduction, convection, and radiation from one body to another. The heat transfer through conduction happens when two bodies with distinguish body temperature come into contact. Whereas convection happens in fluids, say gases and liquids. Here in convection, the heat is transferred through the movement of the particles of the fluid itself from one place to another. Lastly, the heat is transferred through the radioactive particles in the radiation, and they do not require a medium.
As mentioned above that, the flask has a vacuum. The vacuum present in the flask does not allow heat transfer through conduction. At the same time, the screw on the top used for compacting the flask does not allow heat transfer through convection as the motion of fluids particles is restricted through it. The reflective lining on the thermos flask in its inner chamber does not allow any radiation from the hot liquid to transmit. Due to this, thermos flask is also preventive towards heat transfer by radiation.
There is no way to dissipate heat from the flask with these thermos flask features. And the thermos flask is used for keeping a fluid hot for an extended period. And the product stored in the flask remains hot for several hours. Instead of putting any material in a thermos flask to keep the product in the flask hot for long hours. A vacuum is created between two inner lining inside it, which do not allow any heat to dissipate.
From the above-given procedure, we understand that the thermos flask does not allow heat transfer between the hot fluid inside and the cold air in its surroundings. The insulation provided in the flask is why there is no heat transfer, and this is the only principle on which the thermos flask works.
By this, we understood that a thermos flask does not allow any energy or matter from its surrounding by the given principle. This is the cause behind saying a thermos flask is an isolated system.