Newton (unit)
Newton  

Unit system  SI derived unit 
Unit of  Force 
Symbol  N 
Named after  Sir Isaac Newton 
Unit conversions  
1 N in ...  ... is equal to ... 
SI base units  1 kg⋅m/s^{2} 
British Gravitational System  0.2248089 lb_{f} 
The newton (symbol: N) is the International System of Units (SI) derived unit of force. It is named after Isaac Newton in recognition of his work on classical mechanics, specifically Newton's second law of motion.
See below for the conversion factors.
Contents
Definition
One newton is the force needed to accelerate one kilogram of mass at the rate of one metre per second squared in direction of the applied force.
In 1946, Conférence Générale des Poids et Mesures (CGPM) Resolution 2 standardized the unit of force in the MKS system of units to be the amount needed to accelerate 1 kilogram of mass at the rate of 1 metre per second squared. In 1948, the 9th CGPM Resolution 7 adopted the name newton for this force.^{[1]} The MKS system then became the blueprint for today's SI system of units. The newton thus became the standard unit of force in the Système international d'unités (SI), or International System of Units.
This SI unit is named after Isaac Newton. As with every International System of Units (SI) unit named for a person, the first letter of its symbol is upper case (N). However, when an SI unit is spelled out in English, it should always begin with a lower case letter (newton)—except in a situation where any word in that position would be capitalized, such as at the beginning of a sentence or in material using title case. Note that "degree Celsius" conforms to this rule because the "d" is lowercase.— Based on The International System of Units, section 5.2.
Newton's second law of motion states that F = ma, where F is the force applied, m is the mass of the object receiving the force, and a is the acceleration of the object. The newton is therefore:^{[2]}

F = m ⋅ a 1 N = 1 kg ⋅ 1 m/s^{2}
where the following symbols are used for the units: N for newton, kg for kilogram, m for metre, and s for second.
where is force, is mass, is length and is time.
Examples
At average gravity on Earth (conventionally, g = 9.80665 m/s^{2}), a kilogram mass exerts a force of about 9.8 newtons. An averagesized apple exerts about one newton of force, which we measure as the apple's weight.^{[3]}
 1 N = 0.102 kg × 9.80665 m/s^{2} (kg = 102 g) 0.102
The weight of an average adult exerts a force of about 550 – 800 N.
 566 N = 57.7 kg × 9.80665 m/s^{2} (where 57.7 kg is the average Asian adult mass)
 791 N = 80.7 kg × 9.80665 m/s^{2} (where 80.7 kg is average North American adult mass)
Commonly seen as kilonewtons
It is common to see forces expressed in kilonewtons (kN) where 1 kN = 1000 N. For example, the tractive effort of a Class Y steam train locomotive and the thrust of an F100 fighter jet engine are both around 130 kN.
One kilonewton, 1 kN, is 102.0 kgf, or about 100 kg of load.
 1 kN = 102 kg × 9.81 m/s^{2}
So for example, a platform that shows it is rated at 321 kilonewtons (72,000 lb_{f}), will safely support a 32,100 kilograms (70,800 lb) load.
Specifications in kilonewtons are common in safety specifications for:
 the holding values of fasteners, Earth anchors, and other items used in the building industry.
 working loads in tension and in shear.
 rock climbing equipment.
 thrust of rocket engines and launch vehicles
 clamping forces of the various moulds in injection moulding machines used to manufacture plastic parts.
Conversion factors
newton (SI unit) 
dyne 
kilogramforce, kilopond 
poundforce  poundal  

1 N  ≡ 1 kg⋅m/s^{2}  = 10^{5} dyn  ≈ 0.10197 kp  ≈ 0.22481 lbf  ≈ 7.2330 pdl 
1 dyn  = 10^{−5} N  ≡ 1 g⋅cm/s^{2}  ≈ 1.0197 × 10^{−6} kp  ≈ 2.2481 × 10^{−6} lbf  ≈ 7.2330 × 10^{−5} pdl 
1 kp  = 9.80665 N  = 980665 dyn  ≡ g_{n} ⋅ (1 kg)  ≈ 2.2046 lbf  ≈ 70.932 pdl 
1 lbf  ≈ 4.448222 N  ≈ 444822 dyn  ≈ 0.45359 kp  ≡ g_{n} ⋅ (1 lb)  ≈ 32.174 pdl 
1 pdl  ≈ 0.138255 N  ≈ 13825 dyn  ≈ 0.014098 kp  ≈ 0.031081 lbf  ≡ 1 lb⋅ft/s^{2} 
The value of g_{n} as used in the official definition of the kilogramforce is used here for all gravitational units. 
Base  Force  Weight  Mass  

2nd law of motion  m = F/a  F = W ⋅ a/g  F = m ⋅ a  
System  BG  GM  EE  M  AE  CGS  MTS  SI 
Acceleration (a)  ft/s^{2}  m/s^{2}  ft/s^{2}  m/s^{2}  ft/s^{2}  gal  m/s^{2}  m/s^{2} 
Mass (m)  slug  hyl  poundmass  kilogram  pound  gram  tonne  kilogram 
Force (F), weight (W) 
pound  kilopond  poundforce  kilopond  poundal  dyne  sthène  newton 
Pressure (p)  pound per square inch  technical atmosphere  poundforce per square inch  atmosphere  poundal per square foot  barye  pieze  pascal 
Multiples  Prefix name  deca  hecto  kilo  mega  giga  tera  peta  exa  zetta  yotta  

Prefix symbol  da  h  k  M  G  T  P  E  Z  Y  
Factor  10^{0}  10^{1}  10^{2}  10^{3}  10^{6}  10^{9}  10^{12}  10^{15}  10^{18}  10^{21}  10^{24}  
Submultiples  Prefix name  deci  centi  milli  micro  nano  pico  femto  atto  zepto  yocto  
Prefix symbol  d  c  m  μ  n  p  f  a  z  y  
Factor  10^{0}  10^{−1}  10^{−2}  10^{−3}  10^{−6}  10^{−9}  10^{−12}  10^{−15}  10^{−18}  10^{−21}  10^{−24} 
See also
 Force gauge
 International System of Units (SI)
 Joule, SI unit of energy, 1 newton exerted over a distance of 1 metre
 Kilogramforce, force exerted by Earth's gravity at sea level on one kilogram of mass
 Kip (unit)
 Pascal, SI unit of pressure, 1 newton acting on an area of 1 square metre
 Orders of magnitude (force)
 Pound (force)
 Sthène
 Newton metre, SI unit of torque
Notes and references
 ^ International Bureau of Weights and Measures (1977), The international system of units (330–331) (3rd ed.), U.S. Dept. of Commerce, National Bureau of Standards, p. 17, ISBN 0745649742.
 ^ "Table 3. Coherent derived units in the SI with special names and symbols". The International System of Units (SI). International Bureau of Weights and Measures. 2006. Archived from the original on 20070618.
 ^ Whitbread BSc (Hons) MSc DipION, Daisy. "What weighs 100g?". Retrieved 28 August 2015.
 ^ Comings, E. W. (1940). "English Engineering Units and Their Dimensions". Industrial & Engineering Chemistry. 32 (7): 984–987. doi:10.1021/ie50367a028.
 ^ Klinkenberg, Adrian (1969). "The American Engineering System of Units and Its Dimensional Constant g_{c}". Industrial & Engineering Chemistry. 61 (4): 53–59. doi:10.1021/ie50712a010.