fermi | 1 fm | 2 fm | 3 fm | 4 fm | 5 fm | 6 fm | 7 fm | 8 fm | 9 fm | 10 fm | 11 fm | 12 fm | 13 fm | 14 fm | 15 fm | 16 fm | 17 fm | 18 fm | 19 fm | 20 fm | 21 fm | 22 fm | 23 fm | 24 fm | 25 fm | 26 fm | 27 fm | 28 fm | 29 fm | 30 fm | 31 fm | 32 fm | 33 fm | 34 fm | 35 fm | 36 fm | 37 fm | 38 fm | 39 fm | 40 fm | 41 fm | 42 fm | 43 fm | 44 fm | 45 fm | 46 fm | 47 fm | 48 fm | 49 fm | 50 fm | 51 fm | 52 fm | 53 fm | 54 fm | 55 fm | 56 fm | 57 fm | 58 fm | 59 fm | 60 fm | 61 fm | 62 fm | 63 fm | 64 fm | 65 fm | 66 fm | 67 fm | 68 fm | 69 fm | 70 fm | 71 fm | 72 fm | 73 fm | 74 fm | 75 fm | 76 fm | 77 fm | 78 fm | 79 fm | 80 fm | 81 fm | 82 fm | 83 fm | 84 fm | 85 fm | 86 fm | 87 fm | 88 fm | 89 fm | 90 fm | 91 fm | 92 fm | 93 fm | 94 fm | 95 fm | 96 fm | 97 fm | 98 fm | 99 fm | 100 fm |
fathom | 5.4680664916885 × 10-16 ftm | 1.0936132983377 × 10-15 ftm | 1.6404199475066 × 10-15 ftm | 2.1872265966754 × 10-15 ftm | 2.7340332458443 × 10-15 ftm | 3.2808398950131 × 10-15 ftm | 3.827646544182 × 10-15 ftm | 4.3744531933508 × 10-15 ftm | 4.9212598425197 × 10-15 ftm | 5.4680664916885 × 10-15 ftm | 6.0148731408574 × 10-15 ftm | 6.5616797900262 × 10-15 ftm | 7.1084864391951 × 10-15 ftm | 7.655293088364 × 10-15 ftm | 8.2020997375328 × 10-15 ftm | 8.7489063867017 × 10-15 ftm | 9.2957130358705 × 10-15 ftm | 9.8425196850394 × 10-15 ftm | 1.0389326334208 × 10-14 ftm | 1.0936132983377 × 10-14 ftm | 1.1482939632546 × 10-14 ftm | 1.2029746281715 × 10-14 ftm | 1.2576552930884 × 10-14 ftm | 1.3123359580052 × 10-14 ftm | 1.3670166229221 × 10-14 ftm | 1.421697287839 × 10-14 ftm | 1.4763779527559 × 10-14 ftm | 1.5310586176728 × 10-14 ftm | 1.5857392825897 × 10-14 ftm | 1.6404199475066 × 10-14 ftm | 1.6951006124234 × 10-14 ftm | 1.7497812773403 × 10-14 ftm | 1.8044619422572 × 10-14 ftm | 1.8591426071741 × 10-14 ftm | 1.913823272091 × 10-14 ftm | 1.9685039370079 × 10-14 ftm | 2.0231846019248 × 10-14 ftm | 2.0778652668416 × 10-14 ftm | 2.1325459317585 × 10-14 ftm | 2.1872265966754 × 10-14 ftm | 2.2419072615923 × 10-14 ftm | 2.2965879265092 × 10-14 ftm | 2.3512685914261 × 10-14 ftm | 2.405949256343 × 10-14 ftm | 2.4606299212598 × 10-14 ftm | 2.5153105861767 × 10-14 ftm | 2.5699912510936 × 10-14 ftm | 2.6246719160105 × 10-14 ftm | 2.6793525809274 × 10-14 ftm | 2.7340332458443 × 10-14 ftm | 2.7887139107612 × 10-14 ftm | 2.843394575678 × 10-14 ftm | 2.8980752405949 × 10-14 ftm | 2.9527559055118 × 10-14 ftm | 3.0074365704287 × 10-14 ftm | 3.0621172353456 × 10-14 ftm | 3.1167979002625 × 10-14 ftm | 3.1714785651794 × 10-14 ftm | 3.2261592300962 × 10-14 ftm | 3.2808398950131 × 10-14 ftm | 3.33552055993 × 10-14 ftm | 3.3902012248469 × 10-14 ftm | 3.4448818897638 × 10-14 ftm | 3.4995625546807 × 10-14 ftm | 3.5542432195976 × 10-14 ftm | 3.6089238845144 × 10-14 ftm | 3.6636045494313 × 10-14 ftm | 3.7182852143482 × 10-14 ftm | 3.7729658792651 × 10-14 ftm | 3.827646544182 × 10-14 ftm | 3.8823272090989 × 10-14 ftm | 3.9370078740157 × 10-14 ftm | 3.9916885389326 × 10-14 ftm | 4.0463692038495 × 10-14 ftm | 4.1010498687664 × 10-14 ftm | 4.1557305336833 × 10-14 ftm | 4.2104111986002 × 10-14 ftm | 4.2650918635171 × 10-14 ftm | 4.3197725284339 × 10-14 ftm | 4.3744531933508 × 10-14 ftm | 4.4291338582677 × 10-14 ftm | 4.4838145231846 × 10-14 ftm | 4.5384951881015 × 10-14 ftm | 4.5931758530184 × 10-14 ftm | 4.6478565179353 × 10-14 ftm | 4.7025371828521 × 10-14 ftm | 4.757217847769 × 10-14 ftm | 4.8118985126859 × 10-14 ftm | 4.8665791776028 × 10-14 ftm | 4.9212598425197 × 10-14 ftm | 4.9759405074366 × 10-14 ftm | 5.0306211723535 × 10-14 ftm | 5.0853018372703 × 10-14 ftm | 5.1399825021872 × 10-14 ftm | 5.1946631671041 × 10-14 ftm | 5.249343832021 × 10-14 ftm | 5.3040244969379 × 10-14 ftm | 5.3587051618548 × 10-14 ftm | 5.4133858267717 × 10-14 ftm | 5.4680664916885 × 10-14 ftm |
The femtometre (American spelling femtometer, symbol fm derived from the Danish and Norwegian word femten, "fifteen"+Ancient Greek: μέτρον, metrοn, "unit of measurement") is an SI unit of length equal to 10−15 metres, which means a quadrillionth of one. This distance can also be called a fermi and was so named in honour of physicist Enrico Fermi, as it is a typical length-scale of nuclear physics.
Name of unit | Symbol | Definition | Relation to SI units | Unit System |
---|---|---|---|---|
fermi | fm | ≡ 1×10−15 m | ≡ 1×10−15 m | Metric system Non-SI |
fermi | fathoms | fermi | fathoms |
---|---|---|---|
1 | = 5.4680664916885E-16 | 4 | = 2.1872265966754E-15 |
1.5 | = 8.2020997375328E-16 | 4.5 | = 2.4606299212598E-15 |
2 | = 1.0936132983377E-15 | 5 | = 2.7340332458443E-15 |
2.5 | = 1.3670166229221E-15 | 5.5 | = 3.0074365704287E-15 |
3 | = 1.6404199475066E-15 | 6 | = 3.2808398950131E-15 |
A fathom is a unit of length in the imperial and the U.S. customary systems equal to 6 feet (1.8288 metres), used especially for measuring the depth of water.
There are two yards (6 feet) in an imperial fathom. Originally the span of a man's outstretched arms, the size of a fathom has varied slightly depending on whether it was defined as a thousandth of an (Admiralty) nautical mile or as a multiple of the imperial yard. Formerly, the term was used for any of several units of length varying around 5–5 1⁄2 feet.
Name of unit | Symbol | Definition | Relation to SI units | Unit System |
---|---|---|---|---|
fathom | ftm | ≡ 6 ft | = 1.8288 m | Imperial/US |
fathoms | fermi | fathoms | fermi |
---|---|---|---|
1 | = 1.8288E+15 | 4 | = 7.3152E+15 |
1.5 | = 2.7432E+15 | 4.5 | = 8.2296E+15 |
2 | = 3.6576E+15 | 5 | = 9.144E+15 |
2.5 | = 4.572E+15 | 5.5 | = 1.00584E+16 |
3 | = 5.4864E+15 | 6 | = 1.09728E+16 |
fermi | fathoms |
---|---|
1 | = 5.4680664916885 × 10-16 |
1.8288 × 1015 | = 1 |
Symbol | Definition |
---|---|
≡ | exactly equal |
≈ | approximately equal to |
= | equal to |
digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |