In everyday use and in kinematics, the speed of an object is the magnitude of the rate of change of its position with time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity. The average speed of an object in an interval of time is the distance travelled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as the duration of the time interval approaches zero. Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second, but the most common unit of speed in everyday usage is the kilometre per hour or, in the US and the UK, miles per hour. For air and marine travel the knot is commonly used. The fastest possible speed at which energy or information can travel, according to special relativity, is the speed of light in a vacuum c = 299792458 metres per second.
| Common symbols | v |
| SI unit | m/s, m s −1 |
| SI dimension | L T −1 |
關於Speed
All female vocal and dance group from Japan who are known for having sold more than 20 million singles and albums in just three years and eight months. They became the most successful girl group in Asia.
Speed的成就
They briefly disbanded in 2000 but got back together the following year. In 2012, they released their fifth full length studio album 4 Colors.
您不知道JSpeed的熱門事實
Velocity.. Temporal rates.
