Newton metre

From Wikipedia, the free encyclopedia
Jump to: navigation, search

A newton metre is a unit of torque (also called "moment") in the SI system. The symbolic form is N m or N·m,.[1] One newton metre, sometimes hyphenated newton-metre, is equal to the torque resulting from a force of one newton applied perpendicularly to a moment arm which is one metre long.

Torque force equivalence at one meter leverage.png

It is also used less commonly as a unit of work, or energy, in which case it is equivalent to the more common and standard SI unit of energy, the joule.[2] In this very different usage the metre term represents the distance traveled or displacement in the direction of the force, and not the perpendicular distance from a fulcrum as it does when used to express torque. This usage is discouraged by the SI authority, since it can lead to confusion as to whether a given quantity expressed in newton-meters is a torque or a quantity of energy.[3]

Conversion factors[edit]

See also[edit]

References[edit]

  1. ^ BIPM - unit symbols
  2. ^ For example: Eshbach's handbook of engineering fundamentals - 10.4 Engineering Thermodynamics and Heat Transfer "In SI units the basic unit of energy is Newton-metre".
  3. ^ BIPM - special names
  4. ^ Mechanical Engineering Formulas Pocket Guide, p6
  5. ^ Concise encyclopedia of plastics, by Donald V. Rosato, Marlene G. Rosato, Dominick V. Rosato, p621