Write difference between mechanics and thermodynamics.

Explanation

In mechanics motion of particles or bodies under the action of forces and torques be described.
A part that can be described by thermodynamics state variables is known as thermodynamics system.
If the direct effect on a part around a system is known as surrounding (neighbour system). Everything external to the system is the surroundings.
Thermodynamics is not concerned with the motion of the system as a whole, it is concerned with the internal macroscopic state of the body.
When a bullet is fired from a gun, what changes is the mechanical state of the bullet (its kinetic energy) not its temperature. When a bullet pierces a wood and stops the kinetic energy of the bullet gets converted into heat, changing the temperature of the bullet and wood.
Temperature is related to the energy of the internal (disordered) motion of the bullet not to the motion of the bullet as a whole.