What is the SI unit of velocity? A. m B. m/s C. m/s D. m/s^2
The Correct Answer and Explanation is:
Correct Answer: B. m/s
Explanation:
The SI unit of velocity is meters per second (m/s). This unit expresses how far an object travels in one second. Velocity is defined as the rate of change of displacement with respect to time. Unlike speed, which is a scalar quantity, velocity is a vector quantity, meaning it has both magnitude and direction.
In physics, the concept of velocity helps describe how fast an object is moving and in which direction. For example, if a car moves 20 meters to the north in 2 seconds, its velocity is 10 m/s to the north. This distinguishes velocity from speed, which would only state 10 m/s without specifying direction.
The International System of Units (SI) assigns standardized units to all physical quantities. For velocity:
- The unit of displacement (distance in a straight line with direction) is the meter (m).
- The unit of time is the second (s).
Therefore, the SI unit of velocity becomes:Velocity=Displacement (m)Time (s)=m/s\text{Velocity} = \frac{\text{Displacement (m)}}{\text{Time (s)}} = \text{m/s}Velocity=Time (s)Displacement (m)=m/s
This unit shows how many meters an object moves per second. For example, if a ball is rolling at a velocity of 5 m/s, it covers 5 meters every second in a specific direction.
Other units of velocity may be used in different contexts (e.g., kilometers per hour or miles per hour), but m/s remains the standard SI unit used in scientific and academic settings.
It is important to distinguish between velocity and acceleration, which has a different SI unit: meters per second squared (m/s²). Acceleration describes the rate of change of velocity over time, while velocity deals with the rate of change of position.
Hence, the correct SI unit of velocity is m/s.
