NO. although the arrangement of the atoms will change, the total number stays constant.
The answer is D) none of the above
As much as 90% of the matter in the universe my be unseen i.e. dark matter. There is a variety of explanations offered by many astronomers and physicists for this dark matter. It could merely be ordinary material such as ultra-faint stars, cold gas, large or small black holes or dust scattered around the universe, all of which emit or reflect too little radiation for our instruments to detect. It could also consist of exotic, unfamiliar particles that we have not figured out how to observe.
The graph is showing a constant velocity as the line is horizontal. The initial speed is equal to the final speed as there is no changing in acceleration. The second statement is the correct statement
Initial = 2.5 m/s
Final = 2.5 m/s