Which quantity describes how far an object has travelled?

• A. Time
• B. Distance
• C. Speed
• D. Velocity

Answer: (B)

The quantity that describes how far an object has travelled is distance. It measures the total length of the path walked or rolled, regardless of direction, so it’s a scalar value that only has magnitude.

Time tells us how long something lasts, not how far. Speed tells us how fast something moves—that is, distance divided by time—so it describes rate, not total distance. Velocity adds direction to speed, giving how quickly and in what direction the object moves; it’s tied to displacement (the straight-line gap from start to end), which can be smaller than the actual distance travelled if the path isn’t straight.

For example, walking around a 100 m loop once covers 100 m of distance, but your displacement might be zero if you end where you started, and your average velocity would be zero even though you travelled a full loop. That shows why distance is the right quantity for “how far travelled.”