Which one of the following statements about speed and velocity is correct?

In kinematics, physical quantities are classified as either scalar or vector based on their properties. Speed is defined as the distance covered per unit of time and is a scalar quantity because it possesses only magnitude and no specific direction. For example, saying a vehicle moves at 20 m/s describes its speed. In contrast, velocity is defined as the rate of change of displacement over time and is a vector quantity because it includes both magnitude and a specific direction. Velocity essentially describes how fast an object is moving and in what direction. While both share the same SI unit of meters per second (m/s), speed remains a non-zero positive value, whereas velocity can be positive, negative, or zero depending on the direction of displacement [1]. Therefore, speed is scalar and velocity is vector.

Sources

1. [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 8: Measurement of Time and Motion > Speed = Total distance covered Total time taken > p. 113