# Can you?

To all the engineers or the enginnering students out there. How do you give the definition to one meter (1 m)? More: How much do you weight in Newton, slug, and pound-force (lb_f)?

FredGarvin
The meter is a base unit in the SI system. It helps to define other units. Although, according to Wiki, the standard used to define a meter is 1⁄299,792,458 th of a light-second.

In regards to your question about weight, there are 4.448 Newtons in a Lbf. You can do the math from there to convert any other numbers. Be careful, you are including a unit of mass (the slug) in with units of force. They are not interchangeable.

Mech_Engineer
Gold Member
All SI units can be decomposed into http://en.wikipedia.org/wiki/SI_base_unit" [Broken] in the SI system.

Like Fred said, the modern fundamental definition of a meter is 1⁄299,792,458 of a light-second. Historically it was defined as 1/10,000,000 of the distance between the poles of the earth passing through Paris. http://en.wikipedia.org/wiki/Meter

A newton is a unit of force, which is in turn decomposed into three fundamental units- Kilograms, Seconds, and Meters. A Newton can be decomposed into $$\frac{kg*m}{s^2}$$, a defintion that utilizes only fundamental SI units. According to Wikipedia:

Wikipedia.org said:
The newton is the amount of force that is required to accelerate a kilogram of mass at a rate of one meter per second squared.
http://en.wikipedia.org/wiki/Newton

A pound-force is a little less obvious because empirical units are not as clean as SI. however, the general definition according to Wiki:

Wikipedia.org said:
One pound-force is approximately equal to the gravitational force exerted on a mass of one avoirdupois pound on the surface of Earth.
http://en.wikipedia.org/wiki/Pound_force

A slug is a unit of mass that is even harder to visualize, but the basic definition is:

Wikipedia.org said:
The slug is an English unit of mass. It is a mass that accelerates by 1 ft/s² when a force of one pound-force (lbf) is exerted on it. Therefore a slug has a mass of about 32.17405 pound-mass or 14.5939 kg
http://en.wikipedia.org/wiki/Slug_(mass)

Last edited by a moderator: