Momentum in the swing

swingbuster,
I'll go to "physics" with you just a bit here. Momentum is mass times velocity (m X v) and momentum is conserved. The forward momentum can either be transferred to the ground such that the very big M of the earth absorbs it all or it can be transferred to the bat where 200 lbs * 2 feet per second = 2 lbs * 100 feet per second.

Now the reality is that some of the momentum does get transferred to the ground, some gets "lost" in the inefficiencies inherent in transferring the linear momentum of the entire body to rotational momentum of the hips/torso/arms & bat.

However conservation of momentum helps explain why big guys can develop more bat speed even if they aren't "quicker" than the little guys.

The same also applies to pitching. I think it might have been Mickey Lolich who dropped out of pro baseball, developed a pretty good beer gut playing softball and along with it a much faster fastball.

quote:

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Originally posted by CADad:
swingbuster,
I'll go to "physics" with you just a bit here. Momentum is mass times velocity (m X v) and momentum is conserved. The forward momentum can either be transferred to the ground such that the very big M of the earth absorbs it all or it can be transferred to the bat where 200 lbs * 2 feet per second = 2 lbs * 100 feet per second.

Now the reality is that some of the momentum does get transferred to the ground, some gets "lost" in the inefficiencies inherent in transferring the linear momentum of the entire body to rotational momentum of the hips/torso/arms & bat.

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I think quite a bit more explaining is due here. The important aspect of momentum in hitting is the transfer of momentum from the bat to the ball. The factor that really governs this are the velocity vector of the bat during the period of contact between the bat and ball. Coefficients of elasticity are part of the equation. But they can be considered givens, not variables. {This is definitely true for the baseball provided you aren't comparing baseballs of yore to those of today, and we'll ignore the difference in the elasticity of different bats for now.} The velocity of the ball is part of the equation, but for comparative purposes, this can be considered constant. The mass of the ball is constant. So it comes down to the mass of the bat and the velocity vector of the bat.

Conservation of momentum during the time of ball/bat contact doesn't care how the bat speed was generated.

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However conservation of momentum helps explain why big guys can develop more bat speed even if they aren't "quicker" than the little guys.

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Batspeed through the period of contact is what counts, and there is no absolute correlation of size with batspeed.

I'm not following you here.

"Show me a guy who can't pitch inside and I'll show you a loser." Sandy Koufax

quote:

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Originally posted by CADad:
swingbuster,
I'll go to "physics" with you just a bit here. Momentum is mass times velocity (m X v) and momentum is conserved. The forward momentum can either be transferred to the ground such that the very big M of the earth absorbs it all or it can be transferred to the bat where 200 lbs * 2 feet per second = 2 lbs * 100 feet per second.

Now the reality is that some of the momentum does get transferred to the ground, some gets "lost" in the inefficiencies inherent in transferring the linear momentum of the entire body to rotational momentum of the hips/torso/arms & bat.

However conservation of momentum helps explain why big guys can develop more bat speed even if they aren't "quicker" than the little guys.

The same also applies to pitching. I think it might have been Mickey Lolich who dropped out of pro baseball, developed a pretty good beer gut playing softball and along with it a much faster fastball.

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CADad, Lolich pitched for 14 years and then retired for a year at age 36. He sat out a year and then came back for two years as a knuckleball pitcher. He had a beer belly when he was in his 20's though and threw gas. In fact, he always had a big belly on him.

Texan-

I think the point may be that the kinetic chain transfers momentum and sums velocity,lower body to torso to bat.If you have a relly massive lower body and torso,then you can have more momentum in the torso without turning so quick.If you get the massive torso going well with good transfer mechanics,more momentum will transform into batspeed on the approach (from time center of mass of bat leaves arc of handpath until deceleration whic ideally does not happen before contact.Being big/massive will affect/potentially increase batspeed.

Texan,
A heavier person moving at the same speed as a lighter person has more momentum. If they both transfer that momentum as efficiently then the heavier player is going to generate more batspeed. If they both strike the ball as well then the heavier person is going to hit it further than the lighter person. Although there are "smaller" players that transfer momentum more effectively (Aaron) the tendency will always be for the larger player to be able to generate more batspeed. That is part of why many players develop home run power as they gain weight without necessarily getting stronger later in their careers.

The same goes for pitching to a lesser degree. Leverage due to arm length and ability to develop arm speed tend to have more of an effect.

Bbscout,
Thanks for setting me straight on Lolich.

I dont know how Vlad Guerrero and Sammy Sosa can hit. They didn't went to school, how could they learned all those physic's formulas?

ha..ha...ha

"Peace is, the respect for the other people's rights".
Benito Juarez

Racab,
Those who can't do, teach?

Don't get me wrong, my son's hitting instructor was drafted right out of HS and I'll take his 13 years of professional experience and the teaching experience he's had since then over anyone's PhD when it comes to teaching hitting.

Oh, and now that Vlad is on the Angels I'm just looking forward to enjoying the hits and runs. I'm a big believer in pitching so I don't know if they'll be able to beat the A's but the Angels are going to win some games this year even if they don't have the career years they had in 2002.

What about the load to a higher elbow? Do you believe starting the swing with the elbow high and dropping tight to torso is a momentum source of any consequence?

swingbuster-

My guess is the THT/slotting of elbow permits more coil/separation as hands stay back better and bat fires out of arc of handpath faster which would transfer momentum out of torso faster.This should give quicker acceleration.

here is an old batspeed post where Jack mentions dynamic load/exponential resistance(of turning as opposed to dragging bat) which aids in loading/transfer/deceleration:

http://www.batspeed.com/messageboard/output/10593.html

here is a fastpitch hitter with nice synchronization,front viewhttp://home.mindspring.com/~rmk/ULL0002.mpg

clip from mark hansen

side view:

http://home.mindspring.com/~rmk/ULL0003.mpg

THanks as always Tom..added to my TG library.

CADad writes

" posted January 16, 2004 04:36 PM
Texan,
A heavier person moving at the same speed as a lighter person has more momentum. If they both transfer that momentum as efficiently then the heavier player is going to generate more batspeed. If they both strike the ball as well then the heavier person is going to hit it further than the lighter person. Although there are "smaller" players that transfer momentum more effectively (Aaron) the tendency will always be for the larger player to be able to generate more batspeed. That is part of why many players develop home run power as they gain weight without necessarily getting stronger later in their careers."

How true...just watched clips on Frank Thomas while studying swings. His hips don't coil much , not much body action but POW!. Swing doesn't have much eye appeal. Auburn football player first.

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Originally posted by CADad:
Texan,
A heavier person moving at the same speed as a lighter person has more momentum. If they both transfer that momentum as efficiently then the heavier player is going to generate more batspeed. If they both strike the ball as well then the heavier person is going to hit it further than the lighter person. Although there are "smaller" players that transfer momentum more effectively (Aaron) the tendency will always be for the larger player to be able to generate more batspeed. That is part of why many players develop home run power as they gain weight without necessarily getting stronger later in their careers.

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That is not what I thought I read in your first post.

Your assumption is that the player with the larger mass will generate more bat speed. In the real world, there are many other factors (mechanics for instance) that render that assumption oversimplistic. Maybe less oversimplistic when comparing two MLB'ers. But comparing two youth players? I wouldn't bet my paycheck solely based on which of the two was heavier. And I am sure you wouldn't either.

I think we agree that it is the batspeed that counts. The same batspeed - whether produced by a 230 pounder or a 200 punders - will be expected to produce the same distance hit. This does assume that other variables (e.g., same bat, same ball, same pitch speed, same angle of contact, etc.) being held the same between the two.

Is it "bigger" that produces more batspeed? Or "stronger"?

Interesting discussion. I couldn't be sure of what you were meaning in your first post. Thanks for the clarification.

"Show me a guy who can't pitch inside and I'll show you a loser." Sandy Koufax

Texan,
I think the bigger has more of an "impact" (pun intended) than the stronger, although the two tend to go together.

The differences in coordination and timing between youth players can be immense so no I wouldn't bet my paycheck. However, if I had to make a bet and hadn't seen the kids swing or do anything athletic I'd take the bigger kid every time.