What is SI unit of Speed
The correct answer and explanation is:
The SI unit of speed is meters per second, written as m/s.
Speed is defined as the distance traveled by an object per unit of time. In the International System of Units (SI), the base unit for distance is the meter (m), and the base unit for time is the second (s). Therefore, speed is expressed as meters divided by seconds, or meters per second (m/s).
Speed is a scalar quantity, which means it only has magnitude and no direction. It tells how fast an object is moving but not the direction of motion. For example, if a car travels 100 meters in 5 seconds, its speed is calculated by dividing the distance by the time, which is 100 meters รท 5 seconds = 20 meters per second.
The choice of meters per second as the SI unit of speed is convenient because it directly relates the fundamental SI units for length and time. This allows scientists and engineers worldwide to communicate measurements clearly and consistently.
Other units of speed, such as kilometers per hour (km/h), miles per hour (mph), or feet per second (ft/s), are commonly used in daily life but are not SI units. These units can be converted into meters per second for scientific purposes. For example, 1 kilometer per hour equals approximately 0.27778 meters per second.
Speed can also be related to velocity, which is a vector quantity. Velocity has both magnitude and direction. The magnitude of velocity is speed, but velocity also specifies the direction of the object’s movement.
In summary, the SI unit of speed is meters per second (m/s), representing how many meters an object travels in one second. This unit is fundamental in physics and engineering to quantify motion in a standardized way, enabling consistent measurement and analysis across different fields.