On Wed, 17 Dec 2003 14:41:01 GMT, "Bob Swinney" wrote:
Don sez:

"Acceleration is, by definitition, rate of change of velocity with
time AKA dv/dt. If me arse is changing velocity at the moment I
sure don't notice it."

That's because you aren't (we aren't) finely tuned enough to notice the
teensy-tiny interval dv/dt. grin

But we are finely tuned enough to notice the results of non-zero
accelerations. The integral of vt dv/dt is distance traveled in a given
amount of time. When that distance is zero, as it is when we're
sitting on a chair, then dv/dt must also be zero. In other words,
in a static system, acceleration must be zero.

Gary