Specific strength#Tenacity (textile strength)

{{short description|Ratio of strength to mass for a material}}

{{for|the stiffness to weight ratio|specific modulus}}

The specific strength is a material's (or muscle's) strength (force per unit area at failure) divided by its density. It is also known as the strength-to-weight ratio or strength/weight ratio or strength-to-mass ratio. In fiber or textile applications, tenacity is the usual measure of specific strength. The SI unit for specific strength is Pam3/kg, or N⋅m/kg, which is dimensionally equivalent to m2/s2, though the latter form is rarely used. Specific strength has the same units as specific energy, and is related to the maximum specific energy of rotation that an object can have without flying apart due to centrifugal force.

Another way to describe specific strength is breaking length, also known as self support length: the maximum length of a vertical column of the material (assuming a fixed cross-section) that could suspend its own weight when supported only at the top. For this measurement, the definition of weight is the force of gravity at the Earth's surface (standard gravity, 9.80665 m/s2) applying to the entire length of the material, not diminishing with height. This usage is more common with certain specialty fiber or textile applications.

The materials with the highest specific strengths are typically fibers such as carbon fiber, glass fiber and various polymers, and these are frequently used to make composite materials (e.g. carbon fiber-epoxy). These materials and others such as titanium, aluminium, magnesium and high strength steel alloys are widely used in aerospace and other applications where weight savings are worth the higher material cost.

Note that strength and stiffness are distinct. Both are important in design of efficient and safe structures.

Calculations of breaking length

: L=\frac{T_s/\rho}{\mathbf {g} }

where L is the length, T_s is the tensile strength, \rho is the density and \mathbf {g} is the acceleration due to gravity (\approx 9.8 m/s^2)

Examples

class="wikitable sortable" style="text-align:right; margin: 1em auto 1em auto"

|+ Specific tensile strength of various materials

! Material

! data-sort-type="number" | Tensile strength
(MPa)

! data-sort-type="number" | Density
(g/cm3)

! data-sort-type="number" | Specific strength
(kN·m/kg)

! data-sort-type="number" | Breaking length
(km) !! Source

align="left"| Concrete2–52.305.220.44{{CN|date=June 2023}}
align="left"| Polyoxymethylene; POM691.42494.95{{Cite web|url=https://www.azom.com/article.aspx?ArticleID=762|title=Acetal Polyoxymethylene Homopolymer - POM|date=August 30, 2001|website=AZoM.com|access-date=July 22, 2020|archive-date=July 22, 2020|archive-url=https://web.archive.org/web/20200722103423/https://www.azom.com/article.aspx?ArticleID=762|url-status=live}}
align="left"| Rubber150.9216.31.66{{CN|date=June 2023}}
align="left"| Copper2208.9224.72.51{{CN|date=June 2023}}
align="left"| Polypropylene; PP25–400.9028–442.8–4.5{{Cite web|url=http://www.goodfellow.com/E/Polypropylene.html|title=Polypropylene - online catalogue source - supplier of research materials in small quantities - Goodfellow|website=www.goodfellow.com|access-date=2017-04-24|archive-date=2018-08-07|archive-url=https://web.archive.org/web/20180807011205/http://www.goodfellow.com/E/Polypropylene.html|url-status=live}}
align="left"| (Poly)acrylonitrile-butadiene-styrene; ABS41–451.0539–43{{Cite web|url=http://www.goodfellow.com/E/Polyacrylonitrile-butadiene-styrene.html|title=Polyacrylonitrile-butadiene-styrene - online catalogue source - supplier of research materials in small quantities - Goodfellow|website=www.goodfellow.com|access-date=2018-07-29|archive-date=2018-12-20|archive-url=https://web.archive.org/web/20181220212033/http://www.goodfellow.com/E/Polyacrylonitrile-butadiene-styrene.html|url-status=live}}
align="left"| Polyethylene terephthalate; polyester; PET801.3–1.457–62{{Cite web|url=http://www.goodfellow.com/E/Polyethylene-terephthalate.html|title=Polyethylene terephthalate - online catalogue source - supplier of research materials in small quantities - Goodfellow|website=www.goodfellow.com|access-date=2018-07-29|archive-date=2019-04-17|archive-url=https://web.archive.org/web/20190417193244/http://www.goodfellow.com/E/Polyethylene-terephthalate.html|url-status=live}}
align="left"| Piano wire; ASTM 228 Steel1590–33407.8204–428{{Cite web|url=http://www.matweb.com/search/datasheet_print.aspx?matguid=4bcaab41d4eb43b3824d9de31c2c6849|title=ASTM A228 Steel (UNS K08500)|website=www.matweb.com|access-date=2019-01-17|archive-date=2019-01-19|archive-url=https://web.archive.org/web/20190119121710/http://www.matweb.com/search/datasheet_print.aspx?matguid=4bcaab41d4eb43b3824d9de31c2c6849|url-status=live}}
align="left"| Polylactic acid; polylactide; PLA531.2443{{Cite web|url=http://www.goodfellow.com/E/Polylactic-acid-Biopolymer.html|title=Polylactic acid - Biopolymer - online catalogue source - supplier of research materials in small quantities - Goodfellow|website=www.goodfellow.com|access-date=2018-07-29|archive-date=2018-07-29|archive-url=https://web.archive.org/web/20180729230355/http://www.goodfellow.com/E/Polylactic-acid-Biopolymer.html|url-status=live}}
align="left"| Low carbon steel (AISI 1010)3657.8746.44.73{{Cite web |title = AISI 1010 Steel, cold drawn |url = http://www.matweb.com/search/datasheetText.aspx?bassnum=M1010A |website = matweb.com |access-date = 2015-10-20 |archive-date = 2018-04-18 |archive-url = https://web.archive.org/web/20180418115128/http://www.matweb.com/search/datasheetText.aspx?bassnum=M1010A |url-status = live }}
align="left"| Stainless steel (304)5058.0063.16.4{{Cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MQ304A|website = asm.matweb.com|access-date = 2015-10-20|archive-date = 2018-10-01|archive-url = https://web.archive.org/web/20181001114838/http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=mq304a|url-status = live}}
align="left"| Maraging steel (18Ni(350))24508.2298.7829.7{{Cite web|title = SSA Corp Maraging Data Sheet|url =https://matmatch.com/learn/material/maraging-steel |website=matmatch.com/learn/material/maraging-steel }}
align="left"| Brass5808.5567.86.91{{cite web|url=http://www.roymech.co.uk/Useful_Tables/Matter/Copper_Alloys.html|title=Properties of Copper Alloys|work=roymech.co.uk|access-date=2006-04-17|archive-date=2019-03-30|archive-url=https://web.archive.org/web/20190330064952/http://www.roymech.co.uk/Useful_Tables/Matter/Copper_Alloys.html|url-status=live}}
align="left"| Nylon781.1369.07.04{{Cite web|url=http://www.goodfellow.com/E/Polyamide-Nylon-6.html|title=Polyamide - Nylon 6 - online catalogue source - supplier of research materials in small quantities - Goodfellow|website=www.goodfellow.com|access-date=2017-04-24|archive-date=2019-04-17|archive-url=https://web.archive.org/web/20190417193533/http://www.goodfellow.com/E/Polyamide-Nylon-6.html|url-status=live}}
align="left" | Titanium3444.51767.75{{cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MTU020|website = asm.matweb.com|access-date = 2016-11-14|archive-date = 2019-03-22|archive-url = https://web.archive.org/web/20190322124633/http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MTU020|url-status = live}}
align="left" | CrMo Steel (4130)560–6707.8571–857.27–8.70{{Cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=m4130r|website = asm.matweb.com|access-date = 2016-08-18|archive-date = 2019-04-06|archive-url = https://web.archive.org/web/20190406133032/http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=m4130r|url-status = live}}{{Cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=M4130A|website = asm.matweb.com|access-date = 2016-08-18|archive-date = 2012-03-15|archive-url = https://web.archive.org/web/20120315091534/http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=M4130A|url-status = live}}
align="left" | Aluminium alloy (6061-T6)3102.7011511.70{{Cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA6061T6|website = asm.matweb.com|access-date = 2016-08-18|archive-date = 2018-10-22|archive-url = https://web.archive.org/web/20181022154932/http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA6061t6|url-status = live}}
align="left"| Oak900.78–0.69115–13012–13{{cite web |url=http://www.io.tudelft.nl/research/dfs/idemat/Onl_db/Id192p.htm |title=Environmental data: Oak wood |access-date=2006-04-17 |url-status=bot: unknown |archive-url=https://web.archive.org/web/20071009144917/http://www.io.tudelft.nl/research/dfs/idemat/Onl_db/Id192p.htm |archive-date=9 October 2007 }}
align="left"| Inconel (X-750)12508.2815115.4{{Cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=NINC35|website = asm.matweb.com|access-date = 2015-10-20|archive-date = 2018-10-04|archive-url = https://web.archive.org/web/20181004090335/http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=NINC35|url-status = live}}
align="left"| Magnesium alloy2751.7415816.1{{Cite web|url=https://www.efunda.com/Materials/alloys/magnesium/properties.cfm|title=eFunda: Typical Properties of Magnesium Alloys|website=www.efunda.com|access-date=2021-10-01|archive-date=2020-01-30|archive-url=https://web.archive.org/web/20200130045338/http://www.efunda.com/materials/alloys/magnesium/properties.cfm|url-status=live}}
align="left" | Aluminium alloy (7075-T6)5722.8120420.8{{Cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA7075T6|website = asm.matweb.com|access-date = 2015-10-20|archive-date = 2018-10-16|archive-url = https://web.archive.org/web/20181016063536/http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA7075T6|url-status = live}}
align="left" |Pine wood (American eastern white)780.3522322.7{{Cite web|url=http://www.matweb.com/search/datasheet_print.aspx?matguid=1bec7114d2524b63826044c3cc6c344c|title=American Eastern White Pine Wood|website=www.matweb.com|access-date=2019-12-08|archive-date=2019-12-08|archive-url=https://web.archive.org/web/20191208162819/http://www.matweb.com/search/datasheet_print.aspx%3Fmatguid%3D1bec7114d2524b63826044c3cc6c344c|url-status=live}}
align="left" | Titanium alloy (Beta C)12504.8126026.5{{cite web|title = AZo Materials Data Sheet|url = http://www.azom.com/article.aspx?ArticleID=1843|website = azom.com|date = 11 February 2003|access-date = 2016-11-14|archive-date = 2017-06-23|archive-url = https://web.archive.org/web/20170623175914/http://www.azom.com/article.aspx?ArticleID=1843|url-status = live}}
align="left"| Bainite25007.8732132.4

[https://web.archive.org/web/20060828062831/http://www.msm.cam.ac.uk/phase-trans/2005/chunk.html 52nd Hatfield Memorial Lecture: "Large Chunks of Very Strong Steel"] by H. K. D. H. Bhadeshia 2005. [https://archive.today/20121223005514/http://www.msm.cam.ac.uk/phase-trans/2005/chunk.html on archive.is]

align="left" | Reversibly Assembled Cellular Composite Materials

|0.073

|0.0072

|10,139

|1035

|{{Cite web |date=2013-08-16 |title=Toylike blocks make lightweight, strong structures |url=https://www.sciencenews.org/article/toylike-blocks-make-lightweight-strong-structures |access-date=2024-03-21 |language=en-US}}{{Cite journal |last1=Schaedler |first1=Tobias A. |last2=Jacobsen |first2=Alan J. |last3=Carter |first3=Wiliam B. |date=2013-09-13 |title=Toward Lighter, Stiffer Materials |url=https://www.science.org/doi/10.1126/science.1243996 |journal=Science |language=en |volume=341 |issue=6151 |pages=1181–1182 |doi=10.1126/science.1243996 |pmid=24031005 |bibcode=2013Sci...341.1181S |issn=0036-8075|url-access=subscription }}

align="left" | Self-Reprogrammable Mechanical Metamaterials

|0.01117

|0.0103

|1,084

|111

|{{Cite web |last=Krywko |first=Jacek |date=2024-02-08 |title=Building robots for "Zero Mass" space exploration |url=https://arstechnica.com/science/2024/02/building-robots-for-zero-mass-space-exploration/ |access-date=2024-03-21 |website=Ars Technica |language=en-us}}

align="left"| Balsa730.1452153.2{{cite web|url=http://www.matweb.com/search/DataSheet.aspx?MatGUID=368427cdadb34b10a66b55c264d49c23|title=MatWeb – The Online Materials Information Resource|work=matweb.com|access-date=2009-06-29|archive-date=2015-04-02|archive-url=https://web.archive.org/web/20150402150853/http://www.matweb.com/search/DataSheet.aspx?MatGUID=368427cdadb34b10a66b55c264d49c23|url-status=live}}
align="left"| Carbon–epoxy composite12401.5878580.0

McGRAW-HILL ENCYCLOPEDIA OF Science & Technology, 8th Edition, (c)1997, vol. 1 p 375

align="left"| Spider silk14001.311,069109{{CN|date=June 2023}}
align="left"| Silicon carbide fiber34403.161,088110{{Cite web|url=http://www.specmaterials.com/silicarbsite.htm|title=Specialty Materials, Inc SCS Silicon Carbide Fibers|access-date=2006-04-17|archive-date=2018-04-04|archive-url=https://web.archive.org/web/20180404200749/http://www.specmaterials.com/silicarbsite.htm|url-status=live}}
align="left"| Miralon carbon nanotube yarn C-series13750.7–0.91,100112{{Cite web |author=NanoComp Technologies Inc. |title=Miralon Yarn |url=https://cdn2.hubspot.net/hubfs/339583/Offers/Miralon_Yarn.pdf |access-date=2018-12-19 |archive-date=2018-12-20 |archive-url=https://web.archive.org/web/20181220230552/https://cdn2.hubspot.net/hubfs/339583/Offers/Miralon_Yarn.pdf |url-status=live }}
align="left"| Glass fiber34002.601,307133{{cite web|url = http://www.vectranfiber.com/properties/tensile-properties/|title = Vectran|publisher = Vectran Fiber, Inc.|access-date = 2017-06-12|archive-date = 2019-07-08|archive-url = https://web.archive.org/web/20190708154158/https://www.vectranfiber.com/properties/tensile-properties/|url-status = live}}
align="left"| Basalt fiber48402.701,790183{{cite web|url=http://www.rwcarbon.com|title=RWcarbon.com – The Source for BMW & Mercedes Carbon Fiber Aero Parts|work=rwcarbon.com|access-date=2021-10-01|archive-date=2019-05-03|archive-url=https://web.archive.org/web/20190503041337/https://www.rwcarbon.com/|url-status=live}}
align="left"| 1 μm iron whiskers140007.871,800183
align="left"| Vectran29001.402,071211
align="left"| Carbon fiber (AS4)43001.752,457250
align="left"| Kevlar36201.442,514256{{cite web |url=http://www.ngcc.org.uk/info/ch1.html |title=Network Group for Composites in Construction: Introduction to Fibre Reinforced Polymer Composites |access-date=2006-04-17 |url-status=bot: unknown |archive-url=https://web.archive.org/web/20060118112908/http://www.ngcc.org.uk/info/ch1.html |archive-date=January 18, 2006 }}
align="left"| Dyneema (UHMWPE)36000.973,711378{{cite web |title= Dyneema Fact sheet |publisher= DSM |url= http://www.dsm.com/products/dyneema/en_GB/home.html |date= 1 January 2008 |access-date= 23 May 2016 |archive-date= 8 August 2019 |archive-url= https://web.archive.org/web/20190808151151/https://www.dsm.com/products/dyneema/en_GB/home.html |url-status= live }}
align="left"| Zylon58001.543,766384{{Cite web|author=Toyobo Co., Ltd.|title=ザイロン®(PBO 繊維)技術資料 (2005)|url=http://www.toyobo.co.jp/seihin/kc/pbo/technical.pdf|format=free download PDF|archive-url=https://web.archive.org/web/20120426001116/http://www.toyobo.co.jp/seihin/kc/pbo/technical.pdf|archive-date=2012-04-26}}
align="left"| Carbon fiber (Toray T1100G)70001.793,911399{{Cite web|author=Toray Composites Materials America, Co., Ltd.|title=T1100S, INTERMEDIATE MODULUS CARBON FIBER|url=https://www.torayca.com/en/download/pdf/torayca_t1100g.pdf|format=free download PDF|access-date=2021-06-29|archive-date=2021-07-13|archive-url=https://web.archive.org/web/20210713044348/https://www.torayca.com/en/download/pdf/torayca_t1100g.pdf|url-status=live}}
align="left"| Carbon nanotube (see note below)620000.037–1.3446,268–N/A4716–N/A{{Cite journal |first1=Min-Feng |last1=Yu |date=28 January 2000 |title=Strength and Breaking Mechanism of Multiwalled Carbon Nanotubes Under Tensile Load |doi=10.1126/science.287.5453.637 |journal=Science |volume=287 |issue=5453 |pages=637–640 |pmid=10649994 |last2=Lourie |first2=Oleg |last3=Dyer |first3=Mark J. |last4=Moloni |first4=Katerina |last5=Kelly |first5=Thomas F. |last6=Ruoff |first6=Rodney S. |bibcode=2000Sci...287..637Y |s2cid=10758240 |url=http://www.bimat.org/assets/pdf/00_287yu.pdf |archive-url=https://web.archive.org/web/20110304124625/http://www.bimat.org/assets/pdf/00_287yu.pdf |archive-date=4 March 2011 }}{{Cite book |author=K.Hata |title=From Highly Efficient Impurity-Free CNT Synthesis to DWNT forests, CNTsolids and Super-Capacitors |year=2007 |editor1-last=Razeghi |editor1-first=Manijeh |series=Quantum Sensing and Nanophotonic Devices IV |volume=6479 |pages=64791L |chapter=From highly efficient impurity-free CNT synthesis to DWNT forests, CNT solids, and super-capacitors |doi=10.1117/12.716279 |access-date=2009-12-02 |editor2-last=Brown |editor2-first=Gail J |chapter-url=http://www.nanocarbon.jp/english/research/image/review.pdf |archive-url=https://web.archive.org/web/20141214201915/http://www.nanocarbon.jp/english/research/image/review.pdf |archive-date=2014-12-14 |url-status=usurped |s2cid=136421231}}
align="left"| Colossal carbon tube69000.11659,4836066{{cite journal |author1=Peng, H. |author2=Chen, D. |author3=et al., Huang J.Y. | year = 2008 | title = Strong and Ductile Colossal Carbon Tubes with Walls of Rectangular Macropores | journal = Phys. Rev. Lett. | volume = 101 | issue = 14 | pages = 145501 | doi = 10.1103/PhysRevLett.101.145501 | pmid = 18851539 | bibcode=2008PhRvL.101n5501P|display-authors=etal}}
align="left"| Graphene1305002.090 62,4536366{{cite web |url=http://www.nobelprize.org/nobel_prizes/physics/laureates/2010/advanced-physicsprize2010.pdf |title=2010 Nobel Physics Laureates |publisher=nobelprize.org |access-date=2019-03-28 |archive-date=2018-07-01 |archive-url=https://web.archive.org/web/20180701222510/https://www.nobelprize.org/nobel_prizes/physics/laureates/2010/advanced-physicsprize2010.pdf |url-status=live }}
align="left"| Fundamental limit{{val|9|e=13}}{{val|9.2|e=12}}{{cite journal |last=Brown |first=Adam R. |arxiv=1207.3342 |title=Tensile Strength and the Mining of Black Holes |year=2013 |doi=10.1103/PhysRevLett.111.211301 |volume=111 |issue=21 |journal=Physical Review Letters |page=211301 |pmid=24313473 |bibcode=2013PhRvL.111u1301B|s2cid=16394667 }}

The data of this table is from best cases, and has been established for giving a rough figure.

Note: Multiwalled carbon nanotubes have the highest tensile strength of any material yet measured, with labs producing them at a tensile strength of 63 GPa, still well below their theoretical limit of 300 GPa. The first nanotube ropes (20 mm long) whose tensile strength was published (in 2000) had a strength of 3.6 GPa, still well below their theoretical limit.{{cite journal|last1=Li|first1=F.|last2=Cheng|first2=H. M.|last3=Bai|first3=S.|last4=Su|first4=G.|last5=Dresselhaus|first5=M. S.|author-link5=Mildred Dresselhaus|title=Tensile strength of single-walled carbon nanotubes directly measured from their macroscopic ropes|journal=Applied Physics Letters|year=2000|volume=77|issue=20|pages=3161–3163|doi=10.1063/1.1324984|bibcode=2000ApPhL..77.3161L|doi-access=free}} The density is different depending on the manufacturing method, and the lowest value is 0.037 or 0.55 (solid).

The 'Yuri' and space tethers

The International Space Elevator Consortium uses the "Yuri" as a name for the SI units describing specific strength. Specific strength is of fundamental importance in the description of space elevator cable materials. One Yuri is conceived to be the SI unit for yield stress (or breaking stress) per unit of density of a material under tension. One Yuri equals 1 Pa⋅m3/kg or 1 Nm/kg, which is the breaking/yielding force per linear density of the cable under tension.{{Cite web|url=http://www.isec.org/images/StrongTetherChallenge/2013/Handbook-ts2013.rev0.pdf|title=Strong Tether Challenge 2013|archive-url=https://web.archive.org/web/20160114223616/http://www.isec.org/images/StrongTetherChallenge/2013/Handbook-ts2013.rev0.pdf|archive-date=2016-01-14}}{{cite web|url=http://www.isec.org/sec/index.php/about-the-space-elevator/terminology#MegaYuri|title=Terminology|work=isec.org|archive-url=https://web.archive.org/web/20120527065913/http://www.isec.org/sec/index.php/about-the-space-elevator/terminology#MegaYuri|archive-date=2012-05-27}} A functional Earth space elevator would require a tether of 30–80 megaYuri (corresponding to 3100–8200 km of breaking length).{{cite web|url=http://keithcu.com/wiki/index.php/Specific_Strength_in_Yuris|title=Specific Strength in Yuris|work=keithcu.com|access-date=2012-06-02|archive-date=2019-02-09|archive-url=https://web.archive.org/web/20190209124522/http://keithcu.com/wiki/index.php/Specific_Strength_in_Yuris|url-status=live}}

Fundamental limit on specific strength

The null energy condition places a fundamental limit on the specific strength of any material. The specific strength is bounded to be no greater than c2 ≈ {{val|9|e=13|u=kNm/kg}}, where c is the speed of light.

This limit is achieved by electric and magnetic field lines, QCD flux tubes, and the fundamental strings hypothesized by string theory.{{citation needed|date=December 2018}}

Tenacity (textile strength)

{{Anchor|Tenacity}}

Tenacity is the customary measure of strength of a fiber or yarn. It is usually defined as the ultimate (breaking) force of the fiber (in gram-force units) divided by the denier.

Because denier is a measure of the linear density, the tenacity works out to be not a measure of force per unit area, but rather a quasi-dimensionless measure analogous to specific strength.{{cite book |title=Principles of Polymer Systems |first=Ferdinand |last=Rodriguez |page=[https://archive.org/details/principlesofpoly0000rodr/page/282 282] |publisher=Hemisphere Publishing |location=New York |year=1989 |edition=3rd |isbn=9780891161769 |oclc=19122722 |url-access=registration |url=https://archive.org/details/principlesofpoly0000rodr/page/282 }}

A tenacity of 1 corresponds to:{{citation needed|date=December 2018}} \frac{1 {\rm \, g} \cdot 9.80665 {\rm \, m s^{-2}}}{1 {\rm \, g}/9000 {\rm \, m}}=\frac{9.80665 {\rm \, m s^{-2}}}{1/9000 {\rm \, m}}=9.80665 {\rm \, m s^{-2}} \, 9000 {\rm \, m} = 88259.85 {\rm \, m^2 s^{-2}}

Mostly Tenacity expressed in report as cN/tex.

See also

References

{{Reflist|2}}