Answer:
(a) diagram a.(b) the resultant force of a is equal and the resultant force of b is not(unbalanced)
The third sentence is the correct answer, as all the other sentences are incomplete.
Where is the excerpt? If you could let me see it I could help you.
A refutation or contradiction.
This is a bit subjective because this particular work is difficult to classify, but in general many would agree that it is a thematic work of documentation.
