What is the formula for average speed?

• A. Displacement divided by time
• B. Initial velocity multiplied by time
• C. Final velocity minus initial velocity
• D. Total distance divided by time

Answer: (D)

Average speed tells you how quickly you move, regardless of direction. It’s defined as the total distance traveled divided by the total time taken. This uses distance (not displacement) because speed cares about how much ground you cover, not where you end up.

For example, if you drive 60 km, then later another 60 km, you’ve traveled 120 km in whatever total time that took, so your average speed is 120 divided by that total time. The other ideas mix in velocity or changes in speed rather than the actual distance covered over time: displacement over time would give average velocity, and multiplying initial velocity or taking a difference of final and initial velocity does not reflect the distance traveled during the trip. So the correct formula is total distance divided by time.