Gunpowder is a heterogenous mixture,
Reason : the composiotion of the mixture is not uniform throughout, the mixture can be separated by a suitable method , and finally , it composes of charcoal, sulfur and potassium nitrate which is not homogeneous mixture. 
 
        
             
        
        
        
The list of options to answer this question is:
A.kinectic energy is transformed into thermal energy.
B.electrical energy is transformed into potential energy.
C.potential energy is transformed into kinectic energy.
D.mechanical energy is transformed into chemical energy.
The answer is the option A. A.kinectic energy is transformed into thermal energy.
As you know energy cannot be lost but transformed.
When friction force acts over the tyres it increases the speed of the particles in the tyres which is thermal energy, this thermal energy increase comes from kinetic energy loss.
        
             
        
        
        
A) eventually they will be in thermal equilibrium
        
             
        
        
        
ok so this was really confusing, but i think i know the answer. D. ...hairy and ancient hermit crabs and swift, darting minnows and sometimes a
crumbling sand dollar.