What are the standard SI units for velocity?

• A. Meters
• B. Meters per second
• C. Kilograms per second
• D. Meters per hour

Answer: (B)

Velocity is the rate at which position changes, including direction. Because position (displacement) is measured in meters and time in seconds, the SI unit for velocity is meters per second (m/s). This is the unit used for both speed and velocity in SI terms, with velocity simply adding direction to the magnitude. The other options aren’t appropriate SI units for this quantity: meters alone is a unit of length, kilograms per second describes mass flow rate, and meters per hour is a distance-per-time rate but not the SI unit (you can convert it to m/s if needed). Remember, velocity tells you how fast and in what direction something moves, and its unit is m/s.