Re: The sign of g

["John S. Denker" <jsd@MONMOUTH.COM>]

Tina Fanetti wrote:
> One thing I think conveyed to them that acceleration is still acting at the top of the balls flight is that I asked them why would gravity suddenly turn off for this ball at the top?

IMHO the issue here is not the meaning of gravity,
but the meaning of acceleration.

The vernacular meaning of acceleration !!conflicts!! with
the technical physics meaning of acceleration.

vernacular "acceleration" = speeding up
vernacular "deceleration" = slowing down
vernacular "acceleration" does cease at the top of the
trajectory.

Physics acceleration has to do with velocity, not speed.

Squarely facing this conflict is essential.

I wrote up a discussion of this at
  http://www.monmouth.com/~jsd/physics/weight.htm