Velocity and speed
- Velocity is a vector representing how fast, and in what direction, something is traveling.
- Speed is a scalar. It is the magnitude of the velocity.
- Speed just represents how fast something is going.
Velocity is the rate of change of position
| Average velocity: vav |
= |
| Dx
|  |
| Dt
|
|
= |
| xf - xi
| |
| tf - ti
|
|
| Instantaneous velocity: v
|
= |
| dx
| |
| dt
|
|
If the velocity is constant the instantaneous velocity is equal to the average velocity.
The instantaneous velocity is the slope of the line on a position-versus-time graph.
Turning this idea around, the displacement is the area under the curve of the velocity-versus-time graph.