Question

For each of the cases below, describe in one sentence a situation from everyday life (that is, things you have actually seen or experienced) that demonstrates the listed principle or process.

a) The First Law

b) An isothermal process

c) A reversible, adiabatic process

d) An irreversible process

Answer 1

solution:

1.first law :

defination:The first law of thermodynamics is a version of thelaw of conservation of energy, adapted forthermodynamic systems. The law of conservation of energy states that the total energy of an isolated system is constant; energy can be transformed from one form to another, but can be neither created nor destroyed

Thermodynamics is the most present science in your life. In fact, it is so present in your daily life it became common sense. It is much more common sense than the examples given in the other answers (cars, refrigerators, coffee makers, electronic devices, etc, those are all usual applications of thermodynamics, but you don't understand thermodynamics by understanding them).

If you are cooking fish and you accidentally drop the bass (pun intended), you know that it is going straight to the floor. Nobody has to tell you that. How do you know? Because the bass has to go to its state of higher entropy. And you know that it is going to accelerate towards the floor and not drop slowly because it has to conserve energy. You also know that when it hits the floor, you're going to hear a slappy sound because that is how its kinetic energy is dissipated.

When you are cooking, you know the bass is going to get hot because you are transferring energy (in form of heat) to it. And you know you have to eat it otherwise you body will have no way of producing work to get you through your daily job

2.ISOTHERMAL PROCESS:

Take a piston cylinder and compress air in it in such a way that heat developed due to increase in pressure goes out from the walls of the piston. So, the temperature of the system remains constant.

For this to happen you have to move the piston infinetesimally slow.

This is the reason why people say isothermal process are slowest processes.

3. ADIABATIC PROCESS:

I think Xavier is right - all physical systems are in a heat bath of photons with which they can exchange energy. However, if that is just a small correction, I think it would be safe to call that process adiabatic.

I'll throw in an example from astronomy.

When a star goes supernova, the ejected materials go through several different phases of expansion. When the expansion timescale is short compared to the radiative cooling timescale, the ejecta expand roughly adiabatically (with the above caveat, since there is actually some radiative cooling - but it is a small correction). If you're interested in this, the expansion profile is known as a Sedov-Taylor blast wave solution. This is the same expansion profile as from a bomb blast.

REVERSIBLE PROCESS:

we can say , a process is reversible but that is not correct one , whenever a process is taking place there will be some leakage either in mass, energy and momentum. In fact all real process are irreversible in nature.

But some process are there which we can expect it to follow reversible in nature. well key word is if process is reversible in nature , there will be no Entropy generation.

1. Frictionless movement
2. Restrained compression or expansion
3. Electric current flow through zero resistance.

Examples of irreversible processes:

In the physical realm, many irreversible processes are present to which the inability to achieve 100% efficiency in energy transfer can be attributed. The following is a list of spontaneous events which contribute to the irreversibility of processes.^[13]

• Heat transfer through a finite temperature difference
• Friction
• Plastic deformation
• Flow of electric current through a resistance
• Magnetization or polarization with a hysteresis
• Unrestrained expansion of fluids
• Spontaneous chemical reactions
• Spontaneous mixing of matter of varying composition/states