Newton (unit)
-9tyEY5YfsTlHB2k9JS7jOGRWFmg0Ku)
Newton (unit)
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.
Definition
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. 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.
The newton is an named after Isaac Newton. As with every SI unit named for a person, its symbol starts with an upper case letter (N), but when written out it follows no special casing, following whatever would contextually befit a common noun; i.e., "newton" becomes capitalised at the beginning of a sentence and in titles.
In more formal terms, Newton's second law of motion states that the force exerted by an object is directly proportional to the acceleration of that object, namely:[1]
Examples
At average gravity on Earth (conventionally, g = 9.80665 m/s2), a kilogram mass exerts a force of about 9.8 newtons. An average-sized apple exerts about one newton of force, which we measure as the apple's weight.[2]
- 1 N0.10197 kg × 9.80665 m/s()
The weight of an average adult exerts a force of about 608 N.
- 608 N62 kg × 9.80665 m/s(where 62 kg is the world average adult mass)[3]
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 equivalent to 102.0 kgf, or about 100 kg of load under Earth gravity.
- 1 kN102 kg × 9.81 m/s
So for example, a platform that shows it is rated at 321 kilonewtons (72,000 lbf), 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(SIunit) | dyne | kilogram-force, kilopond | pound-force | poundal | |
|---|---|---|---|---|---|
| 1 N | ≡ 1 kg⋅m/s2 | = 105dyn | ≈ 0.10197 kp | ≈ 0.22481 lbf | ≈ 7.2330 pdl |
| 1 dyn | = 10−5N | ≡ 1 g⋅cm/s2 | ≈ 1.0197 × 10−6kp | ≈ 2.2481 × 10−6lbf | ≈ 7.2330 × 10−5pdl |
| 1 kp | = 9.80665 N | = 980665 dyn | ≡gn⋅ (1 kg) | ≈ 2.2046 lbf | ≈ 70.932 pdl |
| 1 lbf | ≈ 4.448222 N | ≈ 444822 dyn | ≈ 0.45359 kp | ≡gn⋅ (1lb) | ≈ 32.174 pdl |
| 1 pdl | ≈ 0.138255 N | ≈ 13825 dyn | ≈ 0.014098 kp | ≈ 0.031081 lbf | ≡ 1 lb⋅ft/s2 |
| The value ofgnas used in the official definition of the kilogram-force is used here for all gravitational units. | |||||
| 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/s2 | m/s2 | ft/s2 | m/s2 | ft/s2 | Gal | m/s2 | m/s2 |
| Mass( m) | slug | hyl | pound-mass | kilogram | pound | gram | tonne | kilogram |
| Force( F),weight] ( W) | pound | kilopond | pound-force | kilopond | poundal | dyne | sthène | newton |
| Pressure( p) | pound per square inch | technical atmosphere | pound-force 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 | 100 | 101 | 102 | 103 | 106 | 109 | 1012 | 1015 | 1018 | 1021 | 1024 | |
| 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 | 100 | 10−1 | 10−2 | 10−3 | 10−6 | 10−9 | 10−12 | 10−15 | 10−18 | 10−21 | 10−24 | |
See also
Force gauge
Joule, SI unit of energy, 1 newton exerted over a distance of 1 metre
Kilogram-force, 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