Re: Pendulum acceleration

[Herb Schulz <herbs@INTERACCESS.COM>]

> In other words, the NET FORCE, and thus the acceleration,
> is zero at the bottom and non-zero at an angle, large or small.

Howdy,

Neither the net force nor the acceleration are zero at the bottom of
the motion.  The net force and acceleration are radial; the
tangential or horizontal components of the net force and acceleration
are zero.

You can do the problem either using horizontal components of forces
and F=ma or tau=I*alpha and the small angle approximation (for SHM).
You get the same conclusion.

Good Luck,
--
Herb Schulz
(herbs@interaccess.com)