Chapter 1 of 10All chapters
Chapter 1 of 10
Describing motion
Position, velocity, acceleration.
The three quantities
Position says where, velocity says how fast and in which direction, acceleration says how quickly velocity is changing. Each is the rate of change of the one before it.
- Turning at constant speed is still accelerating, because direction changes.
- Deceleration is just acceleration pointing the other way.
Graphs
On a position-time graph the slope is velocity. On a velocity-time graph the slope is acceleration and the area underneath is distance travelled. Reading graphs replaces most memorised formulas.