Physics
Acceleration from two velocities
The change in velocity divided by the time over which it happened. The sign of the answer carries the direction.
The Formula
a = (v - u) / t
The change in velocity divided by the time over which it happened. The sign of the answer carries the direction.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| a | Acceleration | m/s^2 | How quickly velocity changes, in metres per second squared. |
| v | Final velocity | m/s | Velocity at the end of the interval. |
| u | Starting velocity | m/s | Velocity at the start of the interval. Zero from rest. |
| t | Time taken | s | The length of the interval in seconds. |
What Each Symbol Means
am/s^2
Acceleration
How quickly velocity changes, in metres per second squared.
vm/s
Final velocity
Velocity at the end of the interval.
um/s
Starting velocity
Velocity at the start of the interval. Zero from rest.
ts
Time taken
The length of the interval in seconds.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate acceleration page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Acceleration, filed under Science. Every number the guide produces comes from substituting into this one line.