Question

which scenario best describes an object with a displacement of zero?
a. a train moves uphill as it travels in a straight path.
a person walks 2 miles north and 2 miles west.
a ball rolls from the top to the bottom of a hill.
a race car starts and ends at the same point on a track.

Explanation:

Displacement is the straight-line distance from an object's starting position to its final position. A displacement of zero means the start and end positions are identical.

• Option A: The train moves to a new uphill position, so start ≠ end.
• Option B: The person ends at a position 2 miles north-west of the start, so start ≠ end.
• Option C: The ball moves from the hilltop to the bottom, so start ≠ end.
• Option D: The race car starts and ends at the same point, so start = end, resulting in zero displacement.

Answer:

D. A race car starts and ends at the same point on a track.