Answer:
Speed is a scalar quantity and no direction is given. It refers "how fast an object is moving. Speed is the measure of time at which an object covers a distance. A fast-moving object has a high speed and covers a relatively large distance in a short amount of time. An object with no movement at all has a zero speed. The units for speed are the following: meter per second, kilometer per hour, and miles per hour.
Explanation:
Before the time of Galileo, people described moving things as simply “slow” or “fast.” Such descriptions were vague. Galileo is credited as being the first to measure speed by considering the distance covered and the time it takes. Speed is how fast an object is moving.
Any combination of units for distance and time that are useful and convenient are legitimate for describing speed:
- miles per hour (mi/h)
- kilometers per hour (km/h)
- centimeters per day
- light-years per century