I knew right away that your answer wasn't right as 1.38 N is a very weak force and would probably be about the strength of sewing thread.
When one has a feel for metric values, one can easily tell if an amount is right or not. Euric ----- Original Message ----- From: "Bill Hooper" <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[EMAIL PROTECTED]> Sent: Saturday, 2004-04-17 12:34 Subject: [USMA:29566] Re: Use of the term "weight" > Recently, in answer to the question: > > "What information do we have when we know that a fishing line is 10 > > pound test?" Is that a pound of mass or a pound of "weight"? > the reply I wrote was: > > First of > > all, it is neither; it is the force that the line can exert without > > breaking (also called the breaking strength). Since it is a force, then > > the equivalent value in metric is 1.38 newtons. > > I think everything I wrote is correct except the numerical value of the > result. It should be: > > "... the equivalent (of 1 pound force) in metric is 4.45 N." > > I make no excuses for my careless error, but it is perhaps of interest > to mention what caused me to make it. I used a chart of conversion > factors that included the pound of force and also the poundal of > force, both units of force in Ye Olde English mix. There being no > standard abbreviation for "poundal" that I know of, the author used > "pdf" which I misunderstood to mean "pound force" (instead of "poundal > force"). Both were given in the table, but I picked the wrong one. > (Pound force was abbreviated "lbf" in the table.) > > The poundal of force is equal to 0.138 N while the pound of force is > equal to 4.45 N. The pound of force in Ye Olde English mix is the force > required to accelerate 1 slug of mass at a rate of 1 foot per second > squared, while a poundal is the force required to accelerate 1 pound of > mass at a rate of 1 foot per second squared. The force of gravity > (sometimes called weight) of a 1 pound mass is equal to a force of 1 > pound force if the conditions are right (in a gravitational field of a > particular, precisely specified strength). > > Confusing? Of course it's confusing ... it is Ye Olde English mixture; > it's supposed to be confusing. :-) > > <><><><><><><><><><><><> > Keep it simple; Make it Metric > <><><><><><><><><><><><> > > Regards, > Bill Hooper > Fernandina Beach, Florida, USA > >
