Answer:
Thermal
Explanation:
Here mechanical energy is defined as
Mechanical energy = Kinetic energy + potential energy
so here we know that mechanical energy is conserved when all forces on an object is conservative in nature
if we have non-conservative forces on the system then that will decrease the mechanical energy.
This decrease in mechanical energy is mainly due to different types of frictional losses
All these frictional losses are always in the form of thermal energy where we will have some heat loss
