Both Average Speed and Average Velocity are two fundamental principles of physics in the chapter on Motion with reference to time and distance. But without basic knowledge about the two, many get confused amongst the two and sometimes even use them interchangeably. If studied properly, one can clearly understand the difference between these two phenomena.
Average Speed vs Average Velocity
The main difference between Average Speed and Average Velocity is that the first one is known to be a scalar quantity, whereas the latter one is a vector quantity. Moreover, the average speed can never be a negative phenomenon. It is either positive or zeroes. Whereas in the case of Average Velocity, it can either be a positive quantity or zero, sometimes even a negative quantity.
The Average Speed of an object can be calculated by dividing the distance it has covered by the time it has taken to cover the latter. The Average Speed can help in determining the average rate that a particular body will take to cover the given distance. The SI unit of the latter is m/s or meters per second.
The Average Velocity can be described as the displacement with reference to the initial or primary position of the object divided by the time taken. Average Velocity is determined to a Vector quantity. The latter has a direction that is the same as that of the direction of the displacement.
Comparison Table Between Average Speed and Average Velocity
| Parameters of Comparison | Average Speed | Average Velocity |
| Definition | The terminology is used to determine how fast or slow a particular object is traveling. | The terminology that is used to define the rate in change of displacement. |
| Direction | Average Speed does not have any specific direction. | Average Velocity does have a specific direction. |
| Quantity | Scalar Quantity. | Vector Quantity. |
| Formula | Divide the total distance traveled by the total time spent. | Total Value of Displacement covered divided by the Total Time Taken. |
| Circular Path | The Average Speed while traversing in a circular path can never be zero. | Average Velocity while traversing in a circular path can be zero. |
What is Average Speed?
The average speed of an object can be described as the phenomenon that occurs over a period of time, separated by the interval’s length. The term “instantaneous speed” is used to define the upper bound of the average speed using the length of the time interval as a metric as the average speed reaches zero. The method for calculating an object’s speed is the distance traveled measured by the time it took to reach that distance.
According to the International System of Units, the unit of speed is m/s or meters per second. But the most common unit that is used for denoting speed in daily purpose usage is k/h or kilometer per hour, and in the United States and the United Kingdom, it is Miles/hour. In both the air and the sea, the unit knot is commonly used for measuring speed and distance.
A speedometer is an instrument that is used to measure and calculate speed. The latter is a scalar quantity. This implies that it has no direction. This phenomenon is used to express how fast or slow a thing is traveling. Speed can never be a negative quantity.
It always is either a positive quantity or zero.
What is Average Velocity?
The fundamental concept of Velocity in kinematics is the branch of classical mechanics that is used to describe the motion and movements of the bodies. Velocity is a physical quantity. And the latter is known to have both magnitude and directions. The absolute scale value or magnitude of the velocity of an object is called speed.
The SI of velocity concerning the metric system is m/s or meters per second. The growth rate in the item’s way with respect to the frame of reference is classified as the velocity of the object. It is a capacity or function of time. The velocity is equal to a definite speed and direction of a particular object.
Velocity can also be defined as a vector quantity. The direction of the latter is comparatively easier to find. The direction of the latter is the same as when compared to that of the direction in which the object is moving.
The acceleration of the body with regard to the time frame divided by the time it took is the method for calculating the average velocity of an object in a given time interval. Displacement is the terminology used to define the change in position of a particular object.
Main Differences Between Average Speed and Average Velocity
- The terminology, Average Speed, is used to determine how fast or slow a particular object is traveling, whereas Average Velocity is the terminology that is used to define the rate in change of displacement.
- Average Speed does not have any specific direction, whereas Average Velocity does have a specific direction.
- Average speed is a scale, whereas average speed is a vector.
- Total length, divided by the amount of time required to traverse the distance, is the formulation for evaluating average speed. However, in the case of average speed, the above formulation is a total displacement value split by total time.
- In the case of the circular path, the Average Speed while traversing in a circular path can never be zero, whereas the average velocity while traversing in a circular path can be zero.
Conclusion
Average Speed and Average Velocity are two very essential fundamental concepts of physics. By virtue of a cumulative distance estimation based on the total time taken, average speeds can be estimated. But, Average Velocity, on the other hand, can be determined by using the formula of the total value of displacement divided by the total time taken. Both of the phenomena have the SI unit m/s or meters per second. Scalar amounts are average rpm.
Nevertheless, the average speed is the quantity of the vector. There is no specific direction to the average speed, but the case of Average Velocity has a specific direction that is considered and taken into account while doing the calculations.
References
- http://chiuphysics.cgu.edu.tw/yun-ju/CGUWeb/SciEdu/Publication/20080221CASE/YJChiuCASE2008%20FullPaper.pdf
- https://www.researchgate.net/profile/Lakshmi_Tharun_Ponnam/publication/306193278_Scilab_Textbook_Companion_for_Principles_of_Physics_by_F_J_Bueche/links/57b34eba08ae030fe246cfa0.pdf