By law of physics, ligher racket x faster swing = heavier racket x slower swing?

Discussion in 'Racquets' started by New Daddy, Sep 1, 2009.

  1. New Daddy

    New Daddy Rookie

    May 14, 2007
    According to the law of physics, the pace of the ball is determined by the momentum of the racket at impact, which is calculated by multiplying the mass of the racket and the velocity of the racket (= M x V).

    Hence, if you are swinging faster with a lighter racket than with a heavier racket, wouldn't it produce the same result on the ball?
    In other words, if a heavier racket slows your swing just a little so that the momentum of your racket at impact ( mass x velocity ) does not improve, would there still be a reason to use a heavier racket?
  2. Fedace

    Fedace Banned

    Dec 10, 2006
    San Diego, CA
    Jimmy connors said yesterday that Hevier racket will swing slower but you will get more power and speed on the shot. Some say he is the smartest man in tennis ever.
  3. cadfael_tex

    cadfael_tex Professional

    Sep 4, 2005
    Fort Leavenworth, KS
    You answered yourself in your post. It's Newtonian physics. Force = mass x acceleration. The higher the mass of the racquet the higher the more potential for force.

    However, it's not that easy. The mass effects the finite amount of acceleration that we are able to produce. For the most part, if you are able to swing both with anywhere near the equivalent force then the heavier racquet will produce more pace.

    That said, I can't swing an 18 oz wooden racquet anymore effectively but can (still think at least) swing a nearly 13oz graphite director (but I feel it).

    All that to say it is a balancing act because we are part of the f=mXa formula.
  4. furyoku_tennis

    furyoku_tennis Hall of Fame

    Mar 4, 2008
    to add on to what the others said, IMO the biggest factor is the player. it's been recommended that players swing the heaviest racquet they can comfortably.
  5. Rexking

    Rexking Professional

    Aug 5, 2008
    1-There is a limit on how fast you can swing a racquet at a given weight.

    2-Say if you have reached the maximum swing speed for a 10oz racquet (i.e. reached maximum power potential at this weight humanly possible), the only way to increase power from there onwards is to increase the weight of the racquet itself.

    -So your theory is correct by law of physic but there is a human factor that need to be considered. See point 1.
  6. Gee

    Gee Professional

    Apr 24, 2006
    The Netherlands
    Conclusion: Play with the heaviest racquet that you can still swing comfortably.
  7. brad1730

    brad1730 Rookie

    Oct 29, 2008
    What about spin? I would think speed is more important than mass - but I'm far from an expert here.
  8. Nellie

    Nellie Hall of Fame

    Oct 4, 2004
    Yes - that's why younger pros are going to lighter racquets to get more head speed for more spin.
  9. stormholloway

    stormholloway Legend

    Nov 30, 2005
    New York City
    The heavier racquet has more potential to achieve greater force because mass is a function of force.
  10. Kevo

    Kevo Hall of Fame

    Feb 3, 2005
    Most high level players can swing just about any frame fast enough to launch a ball into the back fence. What they need is the spin to control the pace. That's why you have to balance weight and speed.

    Also, there is more to the resulting speed of the ball than just the weight of the frame. The collision is inelastic so some energy is lost to other forces. I can only imagine how difficult it would be to quantify them all and arrive at some rule for maximizing pace and spin with a frame.
  11. cadfael_tex

    cadfael_tex Professional

    Sep 4, 2005
    Fort Leavenworth, KS
    That still deals with the force=mass times acceleration formula. They are just emphasizing the acceleration angle. The heavier frame would produce just as much spin if you could swing at the same speed - no? It's just the amount of force we can provide the equation.
  12. prjacobs

    prjacobs Hall of Fame

    Jul 4, 2009
    Theory is one thing.... And I majored in physics before coming to my senses and switching to music:) Obviously, the momentum equation doesn't include flex, because any bending will decrease the amount of mass going forward. Anyway... From my experience, going from a 12.9 oz. racquet to an 11.3 oz. racquet, that was stiffer.... I clearly could hit much harder shots with the lighter racquet. My serves gave my opponents much more trouble and when on defense, I could hit balls that would've gone past me with the heavier racquet and win the point. The ball was simply traveling faster. The best player I ever played used the old Wilson Hammer 2.7 which was light and looked 2" thick. He hit such a hard ball with incredible spin and his kick serves would easily bounce over your head. The theory is correct, but, if you have to be able to swing the heavy racquet fast enough to make it work. In my case I'd have to swing the lighter racquet 14% faster and judging from the results, I easily did that. By the way, I can hit a golf ball 275 yards, so my swing isn't wimpy:) Of, course, that's 275 in any direction:)
  13. Nanshiki

    Nanshiki Hall of Fame

    Jul 4, 2008
    Use the heaviest racquet you can comfortably swing fast. Either way, stay away from racquets in the sub-10-oz category unless you're a grandmother or a very small child.
  14. sureshs

    sureshs Bionic Poster

    Oct 1, 2005
    It is not all that simple. Ever hit with two racquets of similar weights but different balances? The one with the higher SW produces a heavier ball but is difficult to swing faster. If F=ma was all there is to it, there should be no difference. But actually it is the effective mass in the head that is important. That is because your hand and the racquet together form one system. m is not just the mass of the racquet but needs to take distribution into account.
  15. MrAWD

    MrAWD Semi-Pro

    Apr 16, 2006
    Reading, MA
    The energy racquet can create in order to transfer some of it to the ball is proportional with the mass and square of the velocity. In other word, by increasing the mass twice you get twice as much energy as before, but for the velocity once doubled, the energy gets four time bigger!

    This by itself would lead to use as light racquet as possible in order to hit the ball the hardest! But, there is more that happens during the impact. Since the ball has a mass and the velocity (during the rallies at least) it has lots of energy as well. The lighter the racquet is, more effect on it will happen from the ball itself and this is a bad part. That leads to more vibrations and more injuries for the players. And this is especially pronounced for the hits that are not on the sweet spot. So, with a very light racquet you would fell that ball is actually hitting your racquet harder the racquet hits the ball! This would especially be visible at the net, where the racquet speed is pretty low compared to the baseline shots.

    Another problem with the light frames is in the fact that total energy generated is proportional with the square of velocity. That means that smaller variations in velocity create quite visible variation on the amount of energy that goes on the ball. In other words, it is much harder to be consistent with the lighter racquet that needs fast swinging! If you can't have consistency, you are lost before you start unless you play at low levels.

    The last thing that is of importance here is the weight/mass of the racquet is not that important here as the swing weight, but in this content all of the mass labels actually go for the swing weight instead.

    Also, the amount of swing weight or mass that one can handle differs by large between the different guys out there. That is why they are saying that you should swing with the heaviest stick you can handle for the given playing stile. And playing style has a lot to do with the type of racquet one can handle. I believe that is even more important then the size of the guy or his/her muscles.

    At the end there is also a spin factor that complicates things even more...

    Last edited: Sep 1, 2009
  16. diredesire

    diredesire Adjunct Moderator

    Mar 16, 2004
    I think you mean force is a function of mass ;)

    I didn't even bother reading your post after the first few lines, (because) you're right. The p=ma formula is way too simplistic for this sort of system. Simple dynamics is more "ideal" and is used to simplify complicated "stuff" to something we can make sense of, it shouldn't be used as law in the real world, IMHO. There are a lot of variables that really do need to be considered, so no, they are in general, not equal.

    Edit: I should also add that this would make more sense if you were striking the ball straight on, with no spin, but we dont.

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