How does impact accretion contribute to the differentiation of different layers in a planetiesimal? it provides potential energy. it provides mechanical energy. it provides electrical energy. it provides thermal energy.

I think impact accretion provides thermal energy to the differentiation of different layers in a planetiesimal. Accretion is the process through which planets form as material orbiting some stars gathers together through collisions and gravitational or electrostatic attraction, eventually forming larger and larger bodies. Planetesimals are objects that forms through accretion during the early stages of planet formation. They may combine with one another to form protoplanets and eventually planets. 

Except hold on to his or her beliefs even if there is no evidence for those beliefs.