even one (a normal player who's optimal string tension is 24 lbs) hits the shuttlecock on the sweetspot of a 30lb string, the impact is significant enough to affect the accuracy. try a racket which is strung 5lbs more than your own racket and you'll find that. imagine charts with x axis being the tension in lbs, in chart A, y axis is the power, in chart B, y axis is the control, then you have two curves, one being the power-tension curve and the other control-tension curve. (1) less tension more power suggests a bottom-left to top-right power-tension curve; (2) more tension more control suggests a top-left to bottom-right control-tension curve. This is not correct. will you smash harder with a 15lbs racket or control better with a 30lbs racket (let's only talk about the shots that hit the sweetspot) than with the racket you are currently using? 15lbs and 30lbs are extreme, but the model is easily proved to be flawed. In fact, these two curves are bell shape, with x values of the peaks varie from person to person. in this model, the effective range for tension is actually from 0 to the maximum tension the racket and string can withstand. the optimal tensions for power and control (the two numbers may not necessarily be the same) largely depend on how explosive your wrist is (for power) and how much impact your wrist can take (for control).
It depends on what you are trying to accelerate: the entire racket or just the racket head. Since badminton is largely comprising of racket head acceleration, the overal racket weight is a less important factor than welght distribution. Heavier rackets can have an an equal or greater head acceleration than lighter rackets. Imagine a 120g racket with it's entire weight concentrated at the bottom of the handle and the head has zero weight. This racket would have a head acceleration so fast, it would blow your mind. You would be asking yourself: wow, what's happening man, this is like incredible, really incredeeeebubble !
if it were that simple... but a badmintonswing doesn't have one pivot... I count 3: shoulder, elbow and wrist (the fact your whole body moves hardly matters...) so you can't "just accelarate the head" unless you 'dink' (not moving anything except your wrist)... also, from my personal experience..I find the balance more important than the concrete weight...
That is a very strong claim you are making! Do you have data to back it up, or convincing theoretical insight to suggest it? In general, a graph that goes up and then comes down is produced by two competing factors. These two factors must add, not multiply. The only additive factor I can think of is acceleration (adds to tension), but it is not in competition with anything else, and it surely does not depend on string tension. Certainly, the real world is very messy, which is why we need to exercise discipline in trying to understand what goes on. We must look for the largest effect, then the next largest, and so on and so forth, until all effects are exhausted, or we can't be bothered anymore. My claim is that kinematics is the largest effect, which is why I restrict myself to the ideal situation of elastic collisions. A real collision between the shuttle and the racquet is highly inelastic, but to even consider the energetics of the inelastic collision, we have to put the player back in. When I have more time (need to run soon), I can talk about the physics of a kinetic chain, which will hopefully clarify heavy vs light racquets. This will answer your two questions below. However, I do have time to answer the question below: Drop a marble onto a hard concrete floor, and also onto a trampoline. The marble bounces higher (in fact, much higher) from the hard concrete floor than the trampoline. Objects can bounce elastically (if that is what you mean by bouncy) off concrete floors. We can too, if we wrap ourselves tightly in a tight steel shell and don't allow our muscles and skeletons to do anything at all. But we will probably sustain serious injury after rebound. Every object has elastic response (being bouncy), but the range of this elastic response is different for different material. Steel is elastic up to a very large applied force, afterwhich it deforms. A pillow is elastic up to a miniscule applied force, afterwhich it deforms. As objects are deformed, energy is lost, and therefore cannot rebound very high (or even perceptibly). A pillow does not rebound much on a trampoline: kids can bounce on a bed, but a pillow dropped onto a bed will practically stick there. Now back to the trampoline. After bouncing on the trampoline for a few minutes, would you feel tired? Yes, because we have expended energy bouncing. Why are we expending energy? Because the trampoline is not really that elastic, so to bounce high, our muscles actually do work against the trampoline, to pack more energy into the trampoline, so that even after a significant fraction is lost, we still recover enough energy from the trampoline to bounce high. The physics of trampoline bouncing is really that of a forced oscillation (of the trampoline). Some ideas about forced oscillations will be crucial when I get to kinetic chains.
1) I think we are going off the topic now. Please go back and see the origional question. 2) For the origional question, it is too general. I would like to ask Jurong if my re-phrased question is what he is asking. Given 2 racquets with exactly same design, balance points, material, tension and every factors are the same except the overall weight for racquet A is 82g and B is 88g. Given 1 player swing both racquet @ same max force (same swing) and holding both racquets at same place on the handle. Will racquet B produce higher initial shuttle speed than racquet A with the same shuttle? If Jurong has no objection over my question and any one agree, let the answering begin.
I just want to add. The best racquet is the racquet you win most of with. If racquet X can produce the fastest smash for you but you can not get your drop shot tight to the net. You become one trick dog and you will lose at the end when a player can return your smash or another one smash harder than you do. It is the player's skill and experience that win the game.
It can be accepted that the shuttle speed after a collision with the racket is the racket head speed + the captured shuttle speed returned by the string. Since we assume all characteristics, other than the mass, of the rackets are the same, we can safely ignore the captured speed and just examine the racket head speed immediately after the collision. As you will see from my calculations, heavier rackets make a difference. Ding ding ding ding, Doo6's racket is da winnah !!!
u guys are so funny. u forget the fact that racket bends during a swing which adds more physics to it. if u have a heavier racket with the same velocity of swing, did u forget that the racket would unbend in a different velocity than a lighter racket at the same speed? then given all that facts, u gotta take into account the material used to make the racket and the elasticity of that material and itz ability to unbend and so on so forth... good luck... being an engineering major, i'm still too lazy to go figure all these out... would involve many equations not just f=ma. f=ma is an ideal situation given everything is the same. u all forget wind resistance, friction when bird contacts the string so on so forth...
cooldoo6, so your saying u can generate the same head speed with your 120g racket, in a certain time, as the other lighter rackets in question? that sounds a bit fishy minesh
i believe he is only trying to give an ideal case so the guy will get his answer. in rl... ideal cases... err they don't apply. what u learn in college is a bunch of bs in real life cuz itz way more in depth that the general crap u learn.
I am very sorry CoolDoo6, your calc is all wrong again. 1) if same force is given (ie sam torq), racquet head acc will not be the same for light and heavy racquet. 2) just like drowsysmurf said, racquets shaft band. because the head mass for lighter racquet is lighter, the shaft will bend differntly than heavier racquet (not too much, so this factor can be skiped). 3) I thought you posted before that your fake light headed ti-10 racquet smash faster than the head heavy real ti-10. what happen to that observation?
The table ignores the returning of the captured speed, which is the function of the string and racket flex. Different rackets+string combo returns different amount of captured speed. A light racket with higher return can compensate for the missing weight. But lighter flexible rackets have lower stability resulting in poorer accuracy. My claim for the fake was that it offered comparable power but with superior defence. Although I should add: with lower accuracy. Given the same torque, my heavy racket would have higher head speed than the 2 lighter rackets in the table. The racket was specifically designed to have increased head speed. The figure in the table is the worse-scenario for my racket. In practice, the after-impact speed of my heavy racket would be higher than indicated in the table. But i wouldn't like to brag, you know ? Or, jerby might come and laugh at me.
first of all, thank you for your reply and i'm waiting for your more detailed physics. i don't mind, if not will be happier, to be proven wrong, as long as I get the CORRECT answer, it doesn't matter where it is from. well, i drew the graphs in the previous post with logic, reasoning and some common sense, no maths, no physics. are you sure? i have dozens of examples to prove otherwise. ok i'll wait for that. all i tried to say with my pillow example is that, no BIOmechanics. biomechanics can't explain lifeless objects. a chandelier deforms when it drops on the floor but nevertheless, it's very inelastic collision. it doesn't bounce and there's no biomechanics. marble or steel ball, concrete floor or trampoline, when collide, deform. kinetic energy is hence transformed into potential energy and back to kinetic energy to rebound, with different efficiencies. and how do you think the objects store the potential energy? by deformation. deformation is simply the change in shape due to applied forces. the appliced forces can be tensile, compressive, bending or torsion. in the context of badminton, it is compressive (stringbed), bending (shaft and to a little extend, the frame) and very little torsion (shaft and frame when hit off-sweet-spot). deformation first ungergoes elastic, then plastic then fracture where it can't get back any more. you used "deform" when you meant "fracture". btw i don't really like the trampoline analogy for badminton stringbed at all.
this is where i come to say... WHERE THE HECK DO ALL THESE TERMS COME FROM? BIOMECHANICS, BIOPHYSICS? bio deals with life... the body of animals, plants, tissues. how does biomechanics and biophysics work on a racket... you guys really have to explain it to me. i would understand if u say how they work on the arm, waist, legs, wrist. but then again, meh <.<;;; here's biophysics: http://en.wikipedia.org/wiki/Biophysics and here's biomechanics: http://en.wikipedia.org/wiki/Biomechanics -_-;;; i feel noobish for not knowing how these terms apply to the discussion.
you're saying you accelarate your heavy racket faster than a light one? errr... Newton disagrees... now you can counter than by saying it's because it's headlight..But what does headlight mean? Headlight means most/'all' the mass is at the bottom, yet you hit the shuttle with the 'top'... So when it comes to your momentum calculation you treat your arckets as a particle (every force acts upon the same point, no moments, no torques, just dead on, like your train analogy) but when it comes to your swing/wrist torque, then it's not a particle, then it's headlight...
Well, your Mr Newton didn't play badminton. If he did, he would realise rackets with lower MOI have superior angular velocity. For simplicity sake I did not employ MOI and angular velocity for the table as these were close enough to linear velocity and momentum at the point of impact.
True, Sir Isaac Newton (and that is a Sir to you for you British) do not play badminton. However, CoolDoo6 you don't know classic physic either. There is no need to resopnd to any of your post on this question.
Since you appear to know classical physics, would you like to use it to prove a racket with lower MOI doesn't produce higher angular velocity ? As you have the authority of Mr Sir Issac Newton on your side, it shouldn't be that hard for you to prove.
