Newton (unit)

A newton is defined as 1 kg⋅m/s2 (it is a named derived unit defined in terms of the SI base units). One newton is, therefore, the force needed to accelerate one kilogram of mass at the rate of one metre per second squared in the direction of the applied force. The units "metre per second squared" can be understood as measuring a rate of change in velocity per unit of time, i.e. an increase in velocity by one metre per second every second. 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 (SI), or International System of Units. F = ma, where m represents the mass of the object undergoing an acceleration a. When using the SI unit of mass, the kilogram (kg), and SI units for distance metre (m), and time, second (s) we arrive at the SI definition of the newton: 1 kg⋅m/s2. ==Examples==

At average gravity on Earth (conventionally, g_\text{n} = ), a kilogram mass exerts a force of about 9.81 N. • An average-sized apple with mass 200 g exerts about two newtons of force at Earth's surface, which we measure as the apple's weight on Earth. : 0.200 \text{ kg} \times 9.80665 \text{ m/s}^2 = 1.961\text { N}. • An average adult exerts a force of about 608 N on Earth. : 62\text { kg} \times 9.80665 \text{ m/s}^2=608\text{ N} (where 62 kg is the world average adult mass). ==Kilonewtons==

used in rock climbing, with a safety rating of 26 kN when loaded along the spine with the gate closed, 8 kN when loaded perpendicular to the spine, and 10 kN when loaded along the spine with the gate open. Large forces may be expressed in kilonewtons (kN), where . For example, the tractive effort of a Class Y steam train locomotive and the thrust of an F100 jet engine are both around 130 kN. Climbing ropes are tested by assuming a human can withstand a fall that creates 12 kN of force. The ropes must not break when tested against 5 such falls. ==Conversion factors==