Answer :
To determine which of the given options is an example of a velocity, we need to recall the definition of velocity and how it differs from acceleration and speed.
Velocity is a vector quantity that describes the rate of change of position of an object and is specified by both a magnitude (or speed) and a direction. Therefore, in order to be considered a velocity, a measurement must include both of these components.
Let's evaluate the options provided:
A. 12 m/s² east - This option specifies a magnitude of 12 m/s² and a direction (east), but the units m/s² indicate acceleration, not velocity. Acceleration is the rate of change of velocity, not velocity itself. Therefore, this option is not a velocity.
B. 2 km/hr - This option gives a speed, which is the magnitude of velocity, but it does not specify a direction. Since direction is a necessary component of velocity, this cannot be considered a velocity. It is merely a speed.
C. 3 m/s south - This option specifies a magnitude of 3 m/s and a direction (south). This fits the definition of velocity: it is a rate of change of position (3 meters per second) in a specified direction (south). So this is an example of velocity.
D. 8 m/s - Like option B, this is a measure of speed, because it provides a magnitude (8 meters per second) but no direction is specified. In order for this to be a velocity, it would require a direction. Hence, this is not a velocity.
Based on our analysis, the correct answer is option C, 3 m/s south, as it is the only option that represents a velocity, meeting the criteria of having both speed and direction.
