Final answer:
The total distance traveled by the particle is the sum of the outward and return trip, making it 40 units. Since the particle returns to the starting point, the displacement is 0 units.
Step-by-step explanation:
The question you've asked is related to the concepts of distance and displacement in physics. Distance is the total length of the path traveled by an object, regardless of the direction, while displacement is a vector quantity that describes the change in position of the object, having both magnitude and direction.
For the particle that moves from the origin to the point (20, 0) and then back to the point (-20, 0), the total distance traveled is the sum of the lengths of both segments of the journey. This would be 20 units out and 20 units back, totaling 40 units. However, because displacement takes into account the direction, the final displacement would be the difference in position from the starting point, which is zero units, because the particle returns to its starting point.
The correct answer to your question is: Distance: 40 units, Displacement: 0 units.