Time-Mean Speed is defined as the mean of speeds observed at a single location over time. Which option matches this definition?

Time-Mean Speed is defined as the mean of speeds observed at a single location over time. Which option matches this definition?

• A. Arithmetic mean of speeds observed over time at a fixed location
• B. Harmonic mean of speeds
• C. Geometric mean of speeds
• D. Mean of all speeds at one location

Answer: (A)

Time-Mean Speed is the average of speeds measured at a fixed location over a period of time. To get this value, you take the speeds observed at successive times, add them up, and divide by the number of observations—the arithmetic mean. This straight averaging reflects each moment in time contributing equally to the overall speed at that location. The harmonic mean would not represent a simple time-average of speeds (it’s used in different contexts, like averaging rates over equal distances and tends to bias toward slower speeds). The geometric mean is suited for multiplicative changes, not direct time-averaging of instantaneous speeds. So the correct approach is the arithmetic mean of speeds observed over time at that fixed location.

Time-Mean Speed is the average of speeds measured at a fixed location over a period of time. To get this value, you take the speeds observed at successive times, add them up, and divide by the number of observations—the arithmetic mean. This straight averaging reflects each moment in time contributing equally to the overall speed at that location. The harmonic mean would not represent a simple time-average of speeds (it’s used in different contexts, like averaging rates over equal distances and tends to bias toward slower speeds). The geometric mean is suited for multiplicative changes, not direct time-averaging of instantaneous speeds. So the correct approach is the arithmetic mean of speeds observed over time at that fixed location.