Hectometre

The hectometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: hm) or hectometer (American spelling) is an uncommonly used unit of length in the metric system, equal to one hundred metres. It derives from the Greek word "ekato", meaning "hundred". A regulation football or soccer field is approximately 1 hectometre in length.

For area the square hectometer (hm²) is a common unit. It is more commonly known by the name of hectare (ha), meaning 100 ares (100 a). The are is a measurement of area the size of 1 decametre by 1 decametre, which is 10 metres by 10 metres. Hence 100 ares equals an area with dimensions 100 m by 100 m — 1 hectometre by 1 hectometre, the square hectometre — equalling 10,000 square metres (10,000 m²)
For volumes the cubic hectometre (hm³) is also used, 100 m by 100 m by 100 m equalling 1,000,000 cubic metres (1,000,000 m³).
Conversion of units, for comparison with other units

To compare different orders of magnitude this page lists lengths between 100 metres and 1000 metres (1 kilometre).

Conversions

100 metres (sometimes termed a hectometre) is equal to:

100 metres — wavelength of the highest mediumwave radio frequency, 3 MHz
100 metres — spacing of driver location signs on British motorways.
138.8 metres — height of the Great Pyramid of Giza (Pyramid of Cheops)
139 metres — height of the world's tallest roller coaster, Kingda Ka^[2]
187 metres— shortest wavelength of the broadcast radio AM band, 1600 kHz
202 metres — length of the Széchenyi Chain Bridge connecting Buda and Pest
320.75 metres — height of the Eiffel Tower(including antenna) ^[3]
328 metres — height of Auckland's Sky Tower (Auckland), the tallest free-standing structure in the Southern Hemisphere^[when?]
341 metres — height of the world's tallest bridge, the Millau Viaduct^[when?]
390 metres — height of the Empire State Building
400–800 metres — approximate heights of the world's tallest skyscrapers of the past 80 years.^[when?]
458 metres — length of the Knock Nevis, the world's largest supertanker
555 metres — longest wavelength of the broadcast radio AM band, 540 kHz
630 metres — height of the KVLY-TV mast, second tallest structure in the world.
646 metres — height of the Warsaw radio mast, the world's tallest structure until its collapse in 1991.
828 metres — height of Burj Khalifa, world's tallest structure on 17 January 2009^[4]
1000 metres — wavelength of the lowest mediumwave radio frequency, 300 kHz

100 metres — the distance a very fast human being can run in about 10 seconds
100.584 metres — length of a Canadian football field between the goal lines (110 yards)
91.5 metres – 137 metres — length of a soccer field^[5]
105 metres — length of a typical football field
109.73 metres — total length of an American football field (120 yards, including the end zones)
110 – 150 metres the width of an Australian football field
135 – 185 metres the length of an Australian football field
137.16 metres — total length of a Canadian football field, including the end zones (150 yards)

115.5 metres — height of the world's tallest tree in 2007, the Hyperion sequoia^[6]
310 metres — maximum depth of Lake Geneva
340 metres — distance sound travels in air at sea level in one second; see speed of sound
979 metres — height of the Salto Angel, the world's highest free-falling waterfall (Venezuela)

270 metres — length of 99942 Apophis, the smallest known asteroid
535 metres — length of 25143 Itokawa,^[7] a small asteroid visited by a spacecraft

^ Highways Agency. "Driver Location Signs - Frequently Asked Questions". Retrieved 10 February 2010.
^ "Kingda Ka (Six Flags Great Adventure)". Archived from the original on 25 April 2009. Retrieved 18 April 2009. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
^ "Tour Eiffel". Retrieved 15 September 2010.
^ "Burj Dubai all set for 09/09/09 soft opening". Emirates Business 24-7. Archived from the original on 19 January 2009. Retrieved 17 January 2009. {{cite news}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
^ The Laws of The Game
^ http://www.monumentaltrees.com/en/trees/coastredwood/coastredwood/
^ Fujiwara, Akira; et al. (2 June 2006). "The Rubble-Pile Asteroid Itokawa as Observed by Hayabusa". Science. 312 (5778): 1330–1334. doi:10.1126/science.1125841. PMID 16741107. Archived from the original on 2 April 2009. Retrieved 20 April 2009. {{cite journal}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)