The newton (symbol: N) is the SI derived unit of force, named after Isaac Newton in recognition of his work on classical mechanics.

Definition

The newton is the unit of force derived in the SI system; it is equal to the amount of force required to give a mass of one kilogram an acceleration of one metre per second squared. Algebraically:

$\{rm\; 1~N\; =\; 1~frac\{kgcdot\; m\}\{s^2\}\}.$

Examples

• 1 N is the force of earth's gravity on an object with a mass of about 102 g ( kg) (such as a small apple).
• On Earth's surface, a mass of 1 kg exerts a force of approximately 9.80665 N [down] (or 1 kgf). The approximation of 1 kg corresponding to 10 N is sometimes used as a rule of thumb in everyday life and in engineering.
• The decanewton (daN) = 10 N is increasingly used when specifying load bearing capacity of items such as ropes and anti-vibration mounts, being approximately equivalent to the more familiar non-SI unit of force, the kgf.
• The force of Earth's gravity on a human being with a mass of 70 kg is approximately 687 N.
• The dot product of force and distance is mechanical work. Thus, in SI units, a force of 1 N exerted over a distance of 1 m is 1 N·m of work. The Work-Energy Theorem states that the work done on a body is equal to the change in energy of the body. 1 N·m = 1 J (joule), the SI unit of energy.
• It is common to see forces expressed in kilonewtons or kN, where 1 kN = 1 000 N.
• A tonne (metric ton)=(1 000 kg) exerts a force of 9.80665 kN (or 1 000 kgf) under standard gravity conditions on Earth.

Notes

1 kp = 9.80665 N. kp is kilopond 1 kilopond was he measure of 1 kilogram on Earth.

in 1960 this measure was changed to newtons

1 kg on the surface of the Earth weighs 9.8 N, because 1 kg × 9.8 m/s = 9.8 N.

References

• Halliday, Resnick and Walker Fundamentals of Physics, John Wiley & Sons ISBN 0471470619

http://www.sengpielaudio.com/calculator-forceunits.htm

See also

• International System of Units (SI)
• The joule, which is the SI unit of energy, equivalent to 1 newton exerted over a distance of 1 metre.
• The pascal, the SI unit of pressure, equivalent to 1 newton acting on an area of 1 square metre.
• The kilogram-force, which is the force exerted by Earth's gravity at sea level on one kilogram of mass.
• Force gauge