Re: when to write radians

[Ludwik Kowalski <kowalskil@MAIL.MONTCLAIR.EDU>]

On Monday, Jun 30, 2003, at 23:08 US/Eastern, Joe Heafner wrote:

> . . . The rule is this: If the numerical quantity depends on the
> angular unit, then explicitly write the angular unit. If the
> numerical quantity doesn't depend on the angular unit, then
> do not write the unit. Therefore, we don't explicitly write the
> radian when we articulate a value for a linear speed. . . .

1) Decibels are often used to express ratios of two
    physical quantities (expressed in the same units).
    For example, currents, pressures and voltages.

2) When we say "a length of a corridor is 20 meters"
     we are referring to a ratio of two lengths, that of
     the corridor and that of a stick, our secondary
     standard of length. Why don't we add "radians,"
     "decibels" or "machs?" Because this would not
     be useful.

Ludwik Kowalski