Answer:
the decrease in energy is due to the change in the internal energy of the body, which reflects an increase in its temperature.
Step-by-step explanation:
The principle of the conservation of stable energy that energy cannot be created or destroyed but only transformed.
In the case of friction or any other type of dissipative force, the decrease in energy is due to the change in the internal energy of the body, which reflects an increase in its temperature.
This process is due to the breakdown of molecular bonds between the bodies in contact and the spent energy is not fully recoverable from the system.