Posted by: JJA () on Thu Oct 21 19:46:21 2004

>>> Of course, this is the case.
>
> I was merely identifying a contradiction in Jack's previous statements. In his Oct 4 response to Bruce he indicates "bat-head acceleration is exponential rather than linear in nature" with the analogous "acceleration of a dragster is also exponential rather than linear in nature". This suggests rate of velocity change is of power >2 (and possibly increasing):
>
> If c=constant, and vi=0, then vf is:
>
> If a=c, vf=ct
> a=ct, vf=ct*t = ct^2
> a=ct^(>1), vf=ct^(>1)*t = ct^(>2)
>
> He today indicates bat forces applied are constant. If so, bat-head acceleration IS constant, since bat mass does not change (F=ma). <<<
>
> Hi Mike
>
> Tom’s example with gravity should have proved to you that with a constant applied force, the increase in bat velocity is exponential. (F=ma ) also applies to gravity. As the force of gravity remains constant, the velocity of the falling mass increases exponentially.
>
> Jack Mankin
>
>

Mr. Mankin,

Mr. Myers equations of motion for a system with constant acceleration (constant force) are of course correct. Velocity increases linearly with time under constant acceleration. It does not increase exponentially. This is simple physics.

-JJA