what is the S.I unit of speed , time
The correct answer and explanation is:
The S.I. unit of speed is meters per second (m/s). The S.I. unit of time is the second (s).
Speed is defined as the rate at which an object covers distance. It is calculated by dividing the distance traveled by the time taken to travel that distance. Since distance is measured in meters (m) in the International System of Units (S.I.), and time is measured in seconds (s), speed naturally takes the unit meters per second (m/s).
The meter per second unit expresses how many meters an object moves in one second. For example, if a car is moving at a speed of 10 m/s, it means the car travels 10 meters every second.
Time is a fundamental physical quantity that measures the duration of events or the interval between them. The second is the base unit for time in the S.I. system and is widely used in science, engineering, and daily life. It is defined precisely by the vibrations of cesium atoms in atomic clocks. One second is equal to the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two energy levels of the cesium-133 atom.
Having a standard unit of time like the second allows for consistent and accurate measurement of time intervals worldwide. It is crucial for synchronizing clocks, measuring speed, calculating acceleration, and for countless scientific and technological applications.
In summary, speed has the S.I. unit meters per second (m/s), reflecting the distance covered per unit time, while time is measured in seconds (s), providing a standard for quantifying durations and intervals. These units form the foundation for many physical calculations in physics and everyday life.