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@SA_10621772 wrote:
And how to make the MathCAT know that 1 kilogram is equal to 9.81 Newton?
You were already told that this is nonsense! 1 kilogram IS NOT 9.81 Newton!! MASS IS NOT FORCE!
You are confusing kilogram (dimension: mass) with kilogram-force (dimension: force) which also was called Kilopond.
https://en.wikipedia.org/wiki/Kilogram-force
"kgf" is a unit for force which is also pre-defined in Prime
According the unit "ksc" - its defined as Kilogram-force per square centimeter.
https://en.wikipedia.org/wiki/Kilogram-force_per_square_centimetre
This unit is NOT predefined in Prime, but if you need a pressure unit which is not predefined
you always can define your own units. I would suggest doing so at the top of the sheet in a collapsed area and not using the global assignment.
When you define a new unit, you should also label it as "unit" for consistency.
Your statement in the black box is wrong. N does not equal kg. This is physical nonsense, as mass does not equal force. In you equation is Earth's acceleration "hidden", therefore you have "1 kg = 9.81 N"
And how to make the MathCAT know that 1 kilogram is equal to 9.81 Newton?
Is it correct?
Or is there any other way?
@SA_10621772 wrote:
And how to make the MathCAT know that 1 kilogram is equal to 9.81 Newton?
You were already told that this is nonsense! 1 kilogram IS NOT 9.81 Newton!! MASS IS NOT FORCE!
You are confusing kilogram (dimension: mass) with kilogram-force (dimension: force) which also was called Kilopond.
https://en.wikipedia.org/wiki/Kilogram-force
"kgf" is a unit for force which is also pre-defined in Prime
According the unit "ksc" - its defined as Kilogram-force per square centimeter.
https://en.wikipedia.org/wiki/Kilogram-force_per_square_centimetre
This unit is NOT predefined in Prime, but if you need a pressure unit which is not predefined
you always can define your own units. I would suggest doing so at the top of the sheet in a collapsed area and not using the global assignment.
When you define a new unit, you should also label it as "unit" for consistency.
Long ago (~1972) I was reading the comments to an article about converting the USA to metric. One (from a self-proclaimed Professional Engineer) said that he would not use Newtons for force measurement, he would require the designation of a unit of "kilogram force," equal to the force supplied by the weight of one kilogram at the earth's surface, If you look, you can see this philosophy in the "English" units of Mathcad. We have (for mass) "lb" and "lbm". For force we have "lbf", and "ozf". We also have "kgf", so our "Professional Engineer" got his way.
We've spent way too much energy beating this dead horse!
Others have addressed the mass vs force issue. I find that it pays to be explicit. I use lbm or lbf for mass or force when using English units. Never use lb, or worse lbs. Don't get me started on the Slug (English unit of mass).
When using real units, I am sometimes forced (pun not intended) to express kg as a force. In those cases, I use kgf. Mathcad recognizes all of these units.
Hi,
maybe you need this: