Posted by: Mike Myers (mike.myers@bellnexxia.com) on Tue Apr 29 12:48:42 2003

I completely agree that your torque definition is non-contradictory. However, as I indicated, the use of the term (by suggesting a requirement of 2 opposing forces)in your above discussion can be confusing. For example, the successive statements:
> >
> > "One force transferred the body’s rotational energy by the angular displacement of the hands (termed - a circular-hand-path)."
> >
> > "The second force that accelerates the bat-head was torque (causing an object to rotate by forces applied from opposing direction)."
> >
> > True, however, one may conclude by implication, that your first force (CHP) was not torque, since you chose to explicitly call only the second force torque.
> >
> > In reality, both forces are torque examples since in both cases applied forces are 90 degrees to an axis of rotation.
> >
> > Keep up the good work. I enjoy the discussion.
> >
> > Mike.
> >
> >
> >
> > Hello Mike or Jack
>
> >>> I am a little lost as to how a circular hand path produces a force(torque) perpindicular to the bat. Jack's weight on the end of a rope shows how angular acceleration can be created with centripetal force, not torque. I am not a big physics guy, but thought I had a grasp on the forces acting on the bat. Please help me out. <<<
>
> Hi Enloe
>
> You are correct, the chp does not apply a force perpendicular to the bat. The force is directed lengthwise down the center of the bat. The bat will remain perpendicular (or tangent) to the radius of the circular force. Therefore, as the radius arm undergoes angular displacement, so does the bat.
>
> Jack Mankin
>
>
Jack,

In general, this is not true. The CHP does apply a force perpendicular to the bat. The bat acquires angular acceleration and centripetal acceleration due to CHP.

Unless you are considering a case where the batter is no longer forcing the bat in a circular direction (such as follow through at/after contact), then there are always 2 components to circular acceleration:

ac = centripetal acceleration (in direction of radius vector)
at = tangential acceleration (in direction of circular motion)

The total acceleration is the vector sum of these 2 components:

atotal = (ac^2 + at^2)^1/2

Mike.