Distance is the total length of the route travelled and is scalar. Displacement is the straight-line change in position, with direction, and is vector. A return trip can have substantial distance but zero displacement; always identify the start and end positions. Example: Find both quantities after 8 m north and 3 m south. Distance = 11 m; displacement = 5 m north. Distinguish the observation from the explanation, and support any judgement with evidence. Explain the result. Check your reasoning.