Speed is a measure of distance traveled per unit of time. Speed has units of meters per second for distance in a straight line. Speed has the same dimension as speed, and has the same unit as distance divided by time, so one can also be measured in terms of the other. The average speed of an object is the distance traveled per unit time. Speed can be thought of as the rate of change of position with respect to time.
SI unit of speed is meter per second (m/s) but many other unit mile per hour, Kilometer per hour, Feet per Hour, Feet per second, Centimeter per second, Centimeter per hour, Kilometer per hour, Knots, Mach, Centimeter per second, Centimeter per minute.
A knot is a unit of speed equal to one nautical mile per hour, approximately 1.151 mph. The international standard symbol for knot is kn, which is also the SI symbol for the cask (or hogshead) of wine. The term "knot" is also used to refer to some lengths other than the nautical mile.
Mach is a unit used to measure the speed of sound. It is named after the Austrian physicist Ernst Mach. The speed of sound varies depending on the medium through which it travels. In dry air at 20 °C (68 °F), the speed of sound is approximately 343.2 m/s (7687 ft/s). In water, it is about 4,000 m/s (9,800 ft/s). In solids, the speed of sound is slower than in air, and varies with the square of the atomic number of the material. The speed of sound in a gas is only slightly dependent on temperature, increasing by about 0.6 m/s for each degree Celsius increase in temperature.
|1 m/s||2.236 mi/h||3.6 km/h||1.943 knots||0.002915 Mach|
|2 m/s||4.473 mi/h||7.2 km/h||3.887 knots||0.00583 Mach|
|3 m/s||6.710 mi/h||10.8 km/h||5.831 knots||0.00874 Mach|
|4 m/s||8.947 mi/h||14.4 km/h||7.775 knots||0.01166 Mach|
|5 m/s||11.184 mi/h||18 km/h||9.719 knots||0.01457 Mach|
|6 m/s||13.421 mi/h||21.6 km/h||11.663 knots||0.01749 Mach|
|7 m/s||15.658 mi/h||25.2 km/h||13.606 knots||0.020405 Mach|
|8 m/s||17.895 mi/h||28.8 km/h||15.550 knots||0.02332 Mach|
|9 m/s||20.132 mi/h||32.4 km/h||17.494 knots||0.026235 Mach|
|10 m/s||22.369 mi/h||36 km/h||19.438 knots||0.02915 Mach|
|11 m/s||24.606 mi/h||39.6 km/h||21.382 knots||0.032065 Mach|
|12 m/s||26.843 mi/h||43.2 km/h||23.326 knots||0.03498 Mach|
|13 m/s||29.080 mi/h||46.8 km/h||25.269 knots||0.037895 Mach|
|14 m/s||31.317 mi/h||50.4 km/h||27.213 knots||0.04081 Mach|
|15 m/s||33.554 mi/h||54 km/h||29.157 knots||0.043725 Mach|
|16 m/s||35.790 mi/h||57.6 km/h||31.101 knots||0.04664 Mach|
|17 m/s||38.027 mi/h||61.2 km/h||33.045 knots||0.049555 Mach|
|18 m/s||40.264 mi/h||64.8 km/h||34.989 knots||0.05247 Mach|
|19 m/s||42.5017 mi/h||68.4 km/h||36.933 knots||0.055385 Mach|
|20 m/s||44.738 mi/h||72 km/h||38.876 knots||0.05830 Mach|
|30 m/s||67.108 mi/h||108 km/h||58.315 knots||0.08745 Mach|
|40 m/s||89.477 mi/h||144 km/h||77.753 knots||0.011660 Mach|
|50 m/s||111.846 mi/h||180 km/h||97.192 knots||0.014575 Mach|
|60 m/s||134.216 mi/h||216 km/h||116.630 knots||0.01749 Mach|
|70 m/s||156.585 mi/h||252 km/h||136.069 knots||0.20405 Mach|
|80 m/s||178.954 mi/h||288 km/h||155.507 knots||0.23320 Mach|
|90 m/s||201.324 mi/h||324 km/h||174.945 knots||0.26235 Mach|
|100 m/s||223.693 mi/h||364 km/h||194.384 knots||0.2915 Mach|