Paragraph to see if last sentence could act as a summary of the other sentence and if the example explains the main idea. It does. The topic is motion and the paragraph description a ball being moved over time. The other sentences repeat "moved " and "time"
The last sentence include both of those ideas.
Stated main idea: "These are the two important aspects of motion : (1) a change of position and (2) the passage of time "
Paragraph 1 is actually the star of an article . Not only is the sentence a stated main idea and the topic sentence of the paragraph, but it is also the thesis for an article that explains how position and time equal motion