Calculator Input
Enter interval-based time and position data. The form keeps a single-column page layout, while input fields adapt to 3 columns on large screens, 2 on medium, and 1 on mobile.
Formula Used
Interval displacement: Δxi = xend,i − xstart,i
Interval duration: Δti = tend,i − tstart,i
Interval velocity: vi = Δxi ÷ Δti
Average velocity across intervals: vavg = ΣΔxi ÷ ΣΔti = Σ(viΔti) ÷ ΣΔti
Average velocity depends on net displacement, not total path length. If the object reverses direction, some interval displacements may be negative. Those signed values are added together, then divided by the total elapsed time.
This is why average velocity can be smaller than average speed, or even equal zero, when motion ends where it started.
How to Use This Calculator
- Select the distance unit and time unit you want to use.
- Enter the start and end time for each interval.
- Enter the start and end position for the same interval.
- Add as many intervals as needed with the Add Interval button.
- Click Calculate Average Velocity to see the result above the form.
- Review interval velocities, total displacement, total time, and the graph.
- Download the result table with the CSV or PDF buttons.
Example Data Table
| Interval | Start Time (s) | End Time (s) | Start Position (m) | End Position (m) | Displacement (m) | Velocity (m/s) |
|---|---|---|---|---|---|---|
| 1 | 0 | 3 | 0 | 12 | 12 | 4.00 |
| 2 | 3 | 7 | 12 | 20 | 8 | 2.00 |
| 3 | 7 | 10 | 20 | 14 | -6 | -2.00 |
| Total / Average | 14 | 1.40 m/s average velocity | ||||
Here, total displacement is 14 m and total time is 10 s, so average velocity is 14 ÷ 10 = 1.40 m/s.
FAQs
1) What is average velocity with intervals?
It is the overall displacement divided by the total time when motion is split into separate intervals. Each interval can have its own start time, end time, and position change.
2) Is average velocity the same as average speed?
No. Average velocity uses signed displacement, so direction matters. Average speed uses total distance traveled and is always non-negative.
3) Can one interval have negative velocity?
Yes. If the end position is less than the start position during an interval, the displacement is negative, so that interval’s velocity is negative.
4) Do all intervals need the same duration?
No. Intervals can have different durations. The calculator correctly weights each interval by its time when computing the overall average velocity.
5) Do the intervals need to be consecutive?
They should represent the motion segments you want to combine. Consecutive intervals are most common, but the formula still works if intervals are distinct and meaningful.
6) Why does the calculator ask for positions instead of distances?
Velocity depends on displacement, which needs position values with sign and direction. Using positions helps the calculator handle forward and backward motion correctly.
7) What happens if total displacement is zero?
Average velocity becomes zero when the final position equals the initial position, even if the object moved a lot between intervals.
8) Can I use this calculator for lab or tracker data?
Yes. It is useful for experimental motion data, classroom physics tasks, tracker app readings, and interval-based position-time observations.