Editing Speed (section)

= Speed: Definition and Mathematical Representation =

== Introduction ==
'''Speed''' is a fundamental concept in kinematics that refers to how fast an object is moving, regardless of its direction. Unlike velocity, speed is a '''scalar quantity''', meaning it has magnitude but no direction.

Speed helps us understand how quickly an object covers distance over time.

== Definition ==

The instantaneous speed is the magnitude of the velocity vector:

<math>
\text{Speed} = |\vec{v}|
</math>

For average speed over a finite time interval:

<math>
\text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}}
</math>

== SI Unit ==

The SI unit of speed is:

<math>
\mathrm{m/s} \quad \text{(meters per second)}
</math>

Other commonly used units include:
* Kilometers per hour (km/h)
* Miles per hour (mph)
* Centimeters per second (cm/s)

== Speed vs. Velocity ==

* '''Speed''' is a scalar (only magnitude).
* '''Velocity''' is a vector (magnitude + direction).

Example: If an object moves in a circle and returns to its starting point, the average velocity is zero, but the average speed is not.

== Constant and Variable Speed ==

* '''Uniform (Constant) Speed''': The object covers equal distances in equal intervals of time.
* '''Non-uniform Speed''': The object covers unequal distances in equal time intervals.

== Graphical Interpretation ==

* The slope of a distance-time graph gives speed.
* The area under a speed-time graph gives distance.

== Related Formulas ==

* When speed is constant:

<math>
s = vt
</math>

Where:
* <math>s</math> is the distance,
* <math>v</math> is the speed,
* <math>t</math> is the time.

* For variable motion, instantaneous speed can be obtained by:

<math>
\text{Speed} = \lim_{\Delta t \to 0} \frac{\Delta s}{\Delta t}
</math>

== Applications ==

* Road traffic and transportation
* Sports performance (running, cycling, swimming)
* Robotics and automation
* Astronomy (orbital speeds)

== See Also ==
* [[Velocity]]
* [[Acceleration]]
* [[Distance]]
* [[Displacement]]
* [[Kinematics]]