Speed and speed
The quickness and speed are often confused, but their meanings are different. When we speak of speed, we refer to a scalar quantity that relates to the distance traveled over time. While velocity is a vector quantity, it relates displacement with time.
Among the differences that we can say between speed and speed, while both are physical magnitudes, speed evaluates the relationship between distance and time , that is, it is a scalar magnitude. On the other hand, the speed is determined based on the relationship between the space traveled by an object or individual, the travel time and the direction, that is, it is a vector quantity.
Index Speed  Speed  
Definition  It reflects the link between a journey traveled and the time it takes to complete a certain journey.  Speed is a quantity that tells us how fast a body is moving, in what direction and in what direction. 
Features 


Calculation  Speed = distance traveled / time elapsed  Speed = displacement / elapsed time 
Magnitude  Scalar Magnitude: It is described with the use of numerical units  Vectorial Magnitude: It is described with the use of numerical units and the direction 
What is speed:
We can define how speed reflects the link between a journey traveled and the time it takes to complete a certain journey.
What is the average speed?
When we talk about average speed we are referring to the total distance traveled during a certain time. For example, if a car travels 180 km in 6 hours, the average speed comes from dividing 180 by 6, that is: 30 km per hour.
Speed characteristics
 Speed is always positive.
 It is a scalar quantity.
 It takes into account the distance traveled and the time elapsed.
 It does not take into account the address
What is speed:
The speed expresses the relationship between a certain space traveled and the time that is used for it.
What is the average speed?
Average velocity is the displacement of an object from one place to another in a given time.
Speed characteristics
We have said that velocity is a vector magnitude and we can say that among its characteristics we can see that:
 The modulus of velocity is the measure of the value of velocity and that indicates the speed of the body in motion. It is expressed in m / s, Km / h. In maritime navigation the node is used, in Aeronautics or generally with the Mach number.
 Direction indicates where the body is moving. Take into account the address
 The sense is the advancement of the movement.
 Speed is made up of speed and direction, any change implies a change in speed.
Speed and speed in sport
Obviously, in sports, speed is very important for achievement. In sports, speed is the motor quality that determines being able to perform movements as quickly as possible. Expressions of speed are those gestures that have relatively short action times (activated by the energy obtained with an anaerobic mechanism.
The development of this quality is closely linked to the genetic heritage : the possibilities of improving speed depend on the quality of the fibers fast (white fibers) that muscles have.
This quality is conditioned above all by the functionality and efficiency of the nervous system (reaction speed) and the muscular system(speed of contraction ).
Factors that determine the speed of the human being are:
 The perfect neuromotor synchronism between agonist and antagonist muscles;
the nature of muscle fibers: white fibers have greater speed and contraction capacity than red ones;  Quick strength (power), clearly evident in the ability to shoot and jump.
 Muscle elasticity, which allows wider joint movements and, therefore, improves the possibility of making rapid movements given the balance of tension between the agonist and antagonist muscles. Relaxation, mobility and stretching exercises are therefore essential in speed exercises;
 The correct executive technique of the gesture, which avoids unnecessary energy expenditure.
 The mental capacities of concentration and determination.
The speed begins to develop very early, between 1 and 6 years, and has its peak between 13 and 15 years. The best time to develop speed is, therefore, the one before puberty, in which it seems that it is possible to transform at least a small part of the slow fibers into fast fibers, even increasing the potentiality of the fast outputs.