Answer:


Explanation:
The collision is elastic so we can use the conservation of momentum


Describe the motion in axis x'



Describe the motion in axis y'


Heat rises therefore the heat from the fire rises up to your hand... i didnt have any answer choices to work with sorry
As science being dynamic many things will change and due to this changes many things and theories will be new to us. the model of the atom is not weak, it is just developing as time progress because in the early times it is not fully understood because of the lack of technology to study, what scientist do is just filling the knowledge gap of the previous studies.