Speed
Speed is a measure. It is velocity but without the direction.[1][2][3][4]
Finding speed
Speed is the distance an object moves in a given amount of time.[1][2][3] The distance is never negative.[5] If a train takes 1 hour to travel 100 kilometers, it has a speed of 100 kilometers per hour (62 mph). In fact this is the average speed.[3] During this one hour, the train may become slower and faster, it may even drive backwards.[3] The average speed of an object in a certain time is the distance the object traveled divided by the time.[1][3][5] The instantaneous speed is the average speed when the time is very small, almost zero.[3]
Units
There are many units of measurement. Since the 20th century following units were widely used by humans:
- miles per hour (mph),
- kilometers per hour (km/h), and
- meters per second (m/s), which is the SI-unit for speed.
Different units are used for different applications. People controlling planes and ships frequently use Knot (speed).[3] Sometimes a Mach number is used.
Range
The smallest speed is 0 meters per second (0 km/h; 0 mph). A “negative speed” would be in fact a velocity. The biggest speed is the speed of light.[6] You can write bigger speeds, but they are not possible in this universe.
Read also
- Orbital speed
- Speedometer – a thing showing speed
- Speed limit – a law telling people a maximum speed
- Speed of sound
- Wind speed
Speed Media
As an example, a bowling ball's speed when first released will be above its average speed, and after decelerating because of friction, its speed when reaching the pins will be below its average speed.
Sources
- ↑ 1.0 1.1 1.2 speed. The Columbia Electronic Encyclopedia (2017-01-24)Columbia University Press. Retrieved 2022-12-19.
- ↑ 2.0 2.1 velocity. Encyclopaedia Britannica (2022-11-03). Retrieved 2022-12-19.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Glenn Elert. Speed and Velocity. The Physics Hypertextbook (2021). Retrieved 2022-12-19.
- ↑ Kara Rogers. What's the Difference Between Speed and Velocity?. Encyclopaedia Britannica (2016-12-07). Retrieved 2022-12-19.
- ↑ 5.0 5.1 David Darling. speed. Encyclopedia of Science (2021-08-31). Retrieved 2022-12-19.
- ↑ The cosmic speed limit: Why can’t we travel at light speed?. Science World (2015-07-08). Retrieved 2022-12-19.