Re: joules versus newton.meters

[Leigh Palmer <palmer@SFU.CA>]

> 1) Left to my own devices, I write torques as netwon.meters;  on emotional
> grounds I prefer newton.meters to joules.

I prefer foot-pounds or inch-pounds for my devices; I don't own a
torque wrench now, but my old one wasn't SI. On emotional grounds
I have little feeling for newton meters.

> 2) However, emotions are not physics.  The physics says that if I let a
> torque of 5 newton.meters act through an angle of 3 radians, I do 15 joules
> of work.  Therefore a newton.meter is, in a very physical sense, one joule
> per radian.  Shortening this to one joule is perfectly acceptable.

Yup, perfectly acceptable if you are willing to toss out clarity
with that hypothetically dimensionless unit. I claim that it has
substance; one joule per radian means torque in my view, and one
joule does not.

Leigh