Which of these arrows could show a
displacement? Is it (A) the red arrow only, (B)
the green arrow only, or (C) both arrows?
This question asks us which arrow,
the green straight or the red curved one, shows an object’s displacement. We see that both arrows have a
starting point and an endpoint, but that’s where the similarities end. One shows a straight-line path, and
the other shows a meandering path. To answer this question, we must
recall the definition of displacement.
Displacements have several
characteristics. For one, they’re vector quantities,
meaning they have both a magnitude or length and a direction. Look back at the two arrows. Do they both have a length? The answer is yes. Do they both have a direction? The answer is no. The red arrow shows a path that can
only be followed by repeatedly changing direction. There is no single direction that
can be traveled in order to follow a path that has the shape of the red arrow.
So, we must conclude that only the
green arrow represents a displacement. Option (B) is correct.