Velocity is defined as the speed of a moving object in a particular direction. Velocity of an object can also be described as the rate of change of its position with respect to speed and direction of motion (e.g 15 km/h to the south). Velocity is a physical vector quantity; both magnitude and direction are needed to define it. The magnitude of velocity is referred to as speed, being a coherent derived unit whose quantity is measured in the SI Unit as meters per second (m/s).
Speed is the distance traveled per unit of time. It is how fast an object is moving. Speed is a scalar quantity, that is, magnitude of the velocity vector. It doesn’t have direction. Speed can be thought of as the rate at which an object covers distance. Thus, a fast moving object has a high speed and covers a relatively large distance in a given amount of time while a slow-moving object covers a relatively small amount of distance in the same amount of time.
The SI units for speed are m/s (meters per second) though kilometers per hour or miles per hour are common units of speed. For air and marine travel the knot is commonly used.
The Difference
- Speed is the distance covered by a body in unit time whereas velocity is the displacement covered by a body in a unit time.
- Speed is a scalar quantity. Therefore, it only has magnitude. Velocity on the other hand is a vector quantity. Therefore, it has a magnitude and direction as well.
- Speed indicates rapidity of objects whereas velocity indicates both the rapidity and position of the object.
- Speed can also be described as rate of change of distance while velocity can be described as the rate of change of displacement.
- Speed determines how fast an object is moving while velocity determines in which direction an object is moving.
- Speed values can never be zero or negative whereas velocity values can be zero, negative or positive.
- An object can possess different velocities but same speed whereas speed never may or may not equal to velocity.
- The velocity of an object changes with the change in direction, therefore the object must follow one direction. On the other hand, the average speed will continue to count even if the object changes direction.
Also Read: Difference between Distance And Displacement
Speed Vs. Velocity In Tabular Form
BASIS OF COMPARISON | SPEED | VELOCITY |
Description | Speed is the distance covered by a body in unit time. | Velocity is the displacement covered by a body in a unit time. |
Alternative Description | Speed can also be described as rate of change of distance. | Velocity can be described as the rate of change of displacement. |
Magnitude | Speed is a scalar quantity. Therefore, it only has magnitude. | Velocity on the other hand is a vector quantity. Therefore, it has a magnitude and direction as well. |
Indicates | Speed indicates rapidity of objects. | Velocity indicates both the rapidity and position of the object. |
Determines | Speed determines how fast an object is moving. | Velocity determines in which direction an object is moving. |
Values | Speed values can never be zero or negative. | Velocity values can be zero, negative or positive. |
Interrelation | An object can possess different velocities but same speed. | Speed never may or may not equal to velocity. |
Change of Direction | The velocity of an object changes with the change in direction, therefore the object must follow one direction. | The average speed will continue to count even if the object changes direction. |
SI Unit | Meters per second (m/s). | Meters per second (m/s). |
Calculation Formula | Speed= Distance Travelled/Time Taken. | Velocity=Displacement/Time Taken. |
Also Read: Difference Between Scalar And Vector Quantity