Posted by: Louy R. () on Fri Jun 22 17:13:44 2001

> > Since gravity is a consistant force ALL thrown balls start to drop from the path at release the instant it leaves the pitcher's hand. And the speed has nothing to do with it. This is a fundemental unchangeable law of nature and no spin, trajectory or wishfull thinking can change it. THERE IS NO RISE BALL.
>
> Be careful in your use of physics.
> There are two reasons for a ball to 'rise'.
> One is backspin. While backspin creates upward forces on a ball, those upward forces do not necessarily cause the ball to change its path upward of its normal course of flight. The amount of spin on a softball vs. its mass is critical here. Gravity starts pulling the ball down upon release. I suspect that a softball is too heavy to have backspin literally counter the effect of gravity AND additionally make the ball curve up.
> You can throw (or at least hit) a ball that rises with a whiffle ball - it has much less mass and better surface for the spin to interact with the air it moves through.
>
> However the force of gravity acts only on the vertical vector of a thrown or hit ball. To wit, a rifle is aimed to fire at true horizontal. At the moment the bullet exits the barrel, a second bullet is dropped from barrel height. Both hit the ground at the same time. All the force applied to the fired bullet is horizontal. Gravity acts on both bullets as if they are 'standing still' - no vertical momentum except gravity.
> If instead you fire the gun at a 45 degree upward angle, half the momentum is forward, half is upward. Gravity must first counter the upward momentum of the bullet until it stops climbing. At that point the bullet starts to come down. It accelerates due to gravity until it hits the ground - or its velocity levels off when air resistance counters further acceleration.
> The bullet fired up lands much later than a bullet dropped at firing time.
>
> The same holds true for a softball pitch. If the pitch has an upward trajectory, it does not start dropping from release point. It starts losing its upward momentum as the pull of gravity counters its ascent.
> So yes, the ball starts to drop from its original upward path increment by increment due to gravity. But it may still be climbing, albeit more slowly by more slowly, until it levels off.
> A hard thrown softball - 65-70 MPH - can climb for the 35+ feet of a fps pitch. Its not spin, its trajectory
> An upward trajectory does rise.
>
> Backspin diminishes but does not entirely counteract the force of gravity. Backspin balls drop less due to spin.
> Pitches thrown upward rise until gravity stops their rise.
> That's physics reality.
> Lay off the high pitches.
> That's fps reality.

Mark,

Without getting into the application of your accurate description of the science, lets assume that what you are saying is true. Its true, its the application I would argue with.

Consider that no one can throw a softball pitch with a vertical backward spin over 60 miles an hour or problably over 50 mph. The only way to throw a vertical backspin underanded is with the palm down. Don't forgot the basic nature of the physical movements that you are talking about. A 65-70 mph pitch with a vertical backspin cannot be done underhanded unless you use a machine. If there is a superhuman around somewhere who can do it, its not going to happen often enought to have an impact on the game of softball.

The vertical backspin can only be done with a over hand throw. You wil find the math for it in the book "Keep your eye on the ball."


Your half right, but I did learn something from your comments. Thanks
Louy R.