Search results
Results from the WOW.Com Content Network
The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. More simply, the speed of sound is how fast vibrations travel. At 20 °C (68 °F), the speed of sound in air, is about 343 m/s (1,125 ft/s; 1,235 km/h; 767 mph; 667 kn), or 1 km in 2.91 s or one mile in 4.69 s.
Typical speed of a modern high-speed train (e.g. latest generation of production TGV); a diving peregrine falcon—fastest bird; 320 km/h or 200 mph is a parameter sometimes used in defining a supercar.
Miles per hour (mph, m.p.h., MPH, or mi/h) is a British imperial and United States customary unit of speed expressing the number of miles travelled in one hour. It is used in the United Kingdom , the United States , and a number of smaller countries, most of which are UK or US territories, or have close historical ties with the UK or US.
Abbreviations for "kilometres per hour" did not appear in the English language until the late nineteenth century. The kilometre, a unit of length, first appeared in English in 1810, [9] and the compound unit of speed "kilometers per hour" was in use in the US by 1866. [10] "Kilometres per hour" did not begin to be abbreviated in print until ...
Some airspeed indicators in aircraft prior to the mid-1970s indicate in miles per hour plus knots (1 knot = 1.15 mph) or kilometers per hour (1 knot = 1.85 km/h). A primary flight display with the indicated airspeed (IAS) displayed in the form of a vertical "tape" on the left.
1 852.000 metres per hour (exactly), [5] 0.51444 metres per second (approximately), 1.15078 miles per hour (approximately), 20.25372 inches per second (approximately) 1.68781 feet per second (approximately). The length of the internationally agreed nautical mile is 1 852 m. The US adopted the international definition in 1954, having previously ...
Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second (m/s), but the most common unit of speed in everyday usage is the kilometre per hour (km/h) or, in the US and the UK, miles per hour (mph). For air and marine travel, the knot is commonly used.
As of May 15, 2017, 41 states have maximum speed limits of 70 mph (113 km/h) or higher. 18 of those states have 75 miles per hour (121 km/h) speed limits or higher, while 7 states of that same portion have 80 mph (129 km/h) speed limits, with Texas even having an 85 miles per hour (137 km/h) speed limit on one of its toll roads.