enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Supersonic speed - Wikipedia

    en.wikipedia.org/wiki/Supersonic_speed

    During ascent, launch vehicles generally avoid going supersonic below 30 km (~98,400 feet) to reduce air drag. Note that the speed of sound decreases somewhat with altitude, due to lower temperatures found there (typically up to 25 km). At even higher altitudes the temperature starts increasing, with the corresponding increase in the speed of ...

  3. Minute and second of arc - Wikipedia

    en.wikipedia.org/wiki/Minute_and_second_of_arc

    The physical group size equivalent to m minutes of arc can be calculated as follows: group size = tan(⁠ m / 60 ⁠) × distance. In the example previously given, for 1 minute of arc, and substituting 3,600 inches for 100 yards, 3,600 tan(⁠ 1 / 60 ⁠) ≈ 1.047 inches. In metric units 1 MOA at 100 metres ≈ 2.908 centimetres.

  4. North American X-15 - Wikipedia

    en.wikipedia.org/wiki/North_American_X-15

    Release of the X-15 from NB-52A took place at an altitude of about 8.5 miles (13.7 km) (45,000 feet) and a speed of about 500 miles per hour (805 km/h). [8] The X-15 fuselage was long and cylindrical, with rear fairings that flattened its appearance, and thick, dorsal and ventral wedge-fin stabilizers.

  5. Light-second - Wikipedia

    en.wikipedia.org/wiki/Light-second

    Meters Kilometers Miles light-second 1 light-second 299 792 458 m: 2.998 × 10 5 km: 1.863 × 10 5 miles: Average distance from the Earth to the Moon is about 1.282 light-seconds light-minute 60 light-seconds = 1 light-minute 17 987 547 480 m: 1.799 × 10 7 km: 1.118 × 10 7 miles: Average distance from the Earth to the Sun is 8.317 light ...

  6. Orders of magnitude (area) - Wikipedia

    en.wikipedia.org/wiki/Orders_of_magnitude_(area)

    1–4 m 2: Area of the top of an office desk 10 1 10–20 m 2: A parking space 70 m 2: Approximate surface area of a human lung [28] 10 2: 1 square decametre (dam 2) 100 m 2: One are (a) 162 m 2: Size of a volleyball court (18 × 9 metres) [29] 202 m 2: Floor area of a median suburban three-bedroom house in the US in 2010: 2,169 sq ft (201.5 m ...

  7. Milliradian - Wikipedia

    en.wikipedia.org/wiki/Milliradian

    For instance the same angle of 0.1 mrad will subtend 10 mm at 100 meters, 20 mm at 200 meters, etc., or similarly 0.39 inches at 100 m, 0.78 inches at 200 m, etc. Subtensions in mrad based optics are particularly useful together with target sizes and shooting distances in metric units .

  8. Stream gradient - Wikipedia

    en.wikipedia.org/wiki/Stream_gradient

    It is a dimensionless quantity, usually expressed in units of meters per kilometer (m/km) or feet per mile (ft/mi); it may also be expressed in percent (%). The world average river reach slope is 2.6 m/km or 0.26%; [ 2 ] a slope smaller than 1% and greater than 4% is considered gentle and steep, respectively.

  9. Men's 100 metres world record progression - Wikipedia

    en.wikipedia.org/wiki/Men's_100_metres_world...

    One estimate suggests times in the 200 m sprint can be assisted by between 0.09s and 0.14s with the maximum allowable tailing wind of 2.0 m/s, and gain 0.3s at altitudes over 2000m. [14] For this reason, unofficial low-altitude record lists have been compiled.